UnderCover Armor Flex vs Ultra Flex

The UnderCover Ultra Flex is valued for its convenience, providing a quieter, noise-free ride with its carpet-lined panels and LED lighting on both rails.

In contrast, the Armor Flex is known for its superior water and rust resistance due to its unique Line-X coating. While both are hard tri-fold tonneau covers from the same brand, the main distinction lies in the Ultra Flex’s focus on comfort and the Armor Flex’s emphasis on rugged protection.

UnderCover Armor Flex
UnderCover Armor Flex Tonneau Cover

Good things

Ultra Flex

  • LED Lights
  • Carpeted Underside ensures a quiet ride

Armor Flex

  • LINE-X Coating offers great Water and rust Resistance
  • Superior strength
  • Lightweight

Bad things

Ultra Flex

  • Water Leakage issue at Tailgate
  • Weatherstripping may come off with time

Armor Flex

  • Leaks at corners
  • Fitting issues for some truck models
  • Instructions in the manual are not clear

Let’s go through a quick table of specs.

SpecificationUnderCover Armor FlexUnderCover Ultra Flex
Cover TypeHard FoldingHard Folding
DesignLow profileLow profile
LatchingSlam Latches on both sidesSlam Latches
Panel CoreAluminumHigh-Density Foam
Frame MaterialIndustrial Grade AluminumAircraft-Grade Aluminum
Panel ExteriorAluminumAluminum
Included AccessoriesEPDM Rubber seals, drain tubes, prop rodsLights on Rails, Carpeted Finish on the underside of panels
FinishLine-X coating Textured BlackJet black Matte with a Semi-Glossy Look
Weather ResistanceWater-Resistant, Rust ResistantWater-Resistant, UV-Protected
Weight CapacityUp to 400 lbs400 lbs
Cover WeightApproximately 60 lbs70 lbs for standard (Varies by Truck Model)
Bed AccessFull bed accessFull Bed Access
Tailgate SealDual Action Tailgate SealDual-Action Tailgate Seal
Warranty5-Year Limited5-year
Quick Comparison Table – UnderCover Armor Flex vs UnderCover Ultra Flex

Material and Style

Let’s look into the design of the UnderCover Armor Flex tonneau cover. First off, it features a textured black finish. It stays fresh, giving old trucks that new vibe.

UnderCover Armor Flex fully open
UnderCover Armor Flex open at 90° position

The panels of UnderCover Armor Flex are built with sturdy aluminum. Aluminum is known for its durability and lightweight. The frame and rails are also made up of aluminum and are coated matte black to resist rust.

But the standout feature of this cover is that tough LINE-X coating, is the same one boats and trailers use for top-notch protection.

Its sleek, low-profile design not only sharpens the look but also improves your truck’s aerodynamics. You can easily close the Dual Action Tailgate Seal, regardless of your tailgate’s position.

Moreover, if you need full bed space, the prop rods hold it at 90 degrees for effortless access. You can fold it back 2/3 after loading, even though it covers the back windshield.

For the final touch, the EPDM rubber seals. They keep everything watertight and airtight, directing water away. Overall, you can count on Armor Flex for style, durability, and convenience.

For an in-depth look at the UnderCover Armor Flex, check out our detailed review.

On the flip side, the Ultra Flex packs its own impressive features. Its dual aluminum build, coupled with a foam core, offers both durability and insulation. The sleek jet-black powder coating not only protects but also elevates your truck’s look.

The ‘L’ shaped rails anchor the cover firmly and smartly drain away rainwater. Additional protection comes from the EPDM seals and drain tubes, though a tiny hole might be needed for the tubes.

A highlight is the built-in LED light, ensuring clear visibility at night. The carpeted underside looks classy, shields against scratches, and helps maintain a cooler temperature in summer.

The prop rods ensure a rattle-free drive but be aware that a fully raised cover might obscure your third brake light. The slam latches and dual-action tailgate latch offer easy access, whether the cover’s up or down.

All in all, the Ultra Flex stands out with its functionality and smart design.

While we compare the two covers here, you can get a detailed review of the UnderCover Ultra Flex here. Click to read.

Both the UnderCover Armor Flex and Ultra Flex tonneau covers offer durable design features, with Armor Flex boasting a tough LINE-X coating and Ultra Flex incorporating a built-in LED light and carpeted underside. While Armor Flex focuses on protection and aerodynamics, Ultra Flex merges functionality with style. Each cover provides unique benefits, catering to varied user preferences.

Performance in Different Weather

Let’s have a look at how these covers, deal with different weather challenges.

Rain and Wet Conditions

With its EPDM rubber seals, Armor Flex is designed to be watertight, ensuring that the cargo remains dry even during rain. The LINE-X coating also provides an added layer of protection against moisture.

Let’s keep it real, though. During pressure washes or intense storms, you might spot a bit of water sneaking into your truck bed. I’ve noticed it myself, especially near the tailgate side after giving it a good pressure wash.

The ‘L’ shaped rails on Ultra Flex smartly channel rainwater away, and the additional EPDM seals and drain tubes further prevent water ingress. The foam core might offer some insulation against dampness.

Is water leakage an issue? Read our detailed post on it here https://toptonneaureview.com/do-all-tonneau-covers-leak/

I never saw any water inside my truck bed. I’m pretty impressed with the seals. The L-shaped rails do a great job of channeling the water into the drain tubes.

Heat and Sunny Conditions

The LINE-X coating on Armor Flex reflects UV rays, preventing the cover from heating up excessively and protecting the cargo from direct sunlight. The sturdy aluminum build is resistant to warping in heat.

The jet-black powder coating may absorb more heat, but the dual aluminum build and foam core help insulate the truck bed. The carpeted underside can absorb some heat, ensuring the panels are not too hot to touch.

Cold and Snowy Conditions

The LINE-X coating and sturdy aluminum construction ensure that Armor Flex remains rigid and does not crack in cold conditions. Snow can be easily brushed off without damaging the cover.

Its foam core filling provides insulation, which can prevent snow from melting quickly and seeping into the truck bed. The cover’s design allows for easy removal of accumulated snow.

Dusty and Windy Conditions

The tight fit and rubber seals ensure that dust and wind don’t easily penetrate, keeping the cargo clean. The textured black finish also masks any dust accumulation.

The sleek design and EPDM seals effectively keep out dust. The carpeted underside helps trap any dust or debris, ensuring the cargo remains clean.

The Armor Flex, with its LINE-X coating, might have a slight edge in extreme conditions due to its enhanced protective properties. In contrast, Ultra Flex offers insulation and features designed for ease of use and aesthetics, making it a solid choice for daily use in varied climates.

Which Cover offers better Security?

UnderCover Armor Flex Cover Installed on Toyota Tcaoma
UnderCover Armor Flex Cover Installed

Let’s talk about the security of both covers. The UnderCover Armor Flex has a solid aluminum core which is impenetrable. The Dual Action Tailgate Seal ensures that the cover is locked properly with the tailgate, and will only unlock when you unlock the tailgate.

But in all honesty, while it’s miles better than an open bed, no cover is foolproof. I’ve parked both downtown and out in the wild, and having this lid does give me a bit more confidence.

I’ve felt the need for a stronger locking system. While Armor Flex doesn’t make your truck bed invincible, it certainly boosts its security. It’s something to think about, in my opinion.

Now digging into the UnderCover Ultra Flex’s security, its dual aluminum build is a solid first defense against break-ins. The ‘L’ shaped rails ensure a tight fit, making casual tampering difficult.

Though the slam latches and dual-action tailgate latch provide easy access for owners, they pose a challenge to outsiders. While no cover is foolproof, the Ultra Flex’s design offers a significant deterrent to potential thieves.

I used to follow a few steps and I never had any issues regarding security.

  • Always be vigilant. Park in well-lit areas, keep your tailgate locked
  • Ensure your cover is always securely clamped down.
  • Check if the seals are tight, before leaving your truck in a parking for hours.
  • Lock your tailgate. Every layer of protection counts.

Both the UnderCover Armor Flex and UnderCover Ultra Flex come from the same brand, so their security features are pretty comparable. Essentially, either cover offers a similar level of protection for your truck bed.

Usage and Ride Comfort

Let’s talk about the impact of UnderCover Armor Flex and UnderCover Ultra Flex on everyday life.

Vehicle Aerodynamics

The UnderCover Armor Flex, with its streamlined design, is a game-changer when it comes to decreasing drag. This isn’t just about looks; the reduced air resistance can lead to potential savings at the fuel pump.

On the other hand, the UnderCover Ultra Flex is made with aerodynamics in mind. It has a smooth jet-black powder coating, this cover is designed to glide through the wind effortlessly.

Not only does it look sharp, but its shape and finish might provide an edge in minimizing turbulence and improving overall vehicle efficiency.

Both covers clearly prioritize performance without sacrificing aesthetics.


UnderCover Ultra Flex carpet lining
UnderCover Ultra Flex carpeted underside

The Armor Flex features EPDM rubber seals, which expertly reduce vibrations, contributing to a hushed and peaceful drive. Proper installation should mitigate most road noise.

Meanwhile, the Ultra Flex steps up with the foam core insulation, it can act as a buffer against noise. The carpeted underside further dampens sounds, promising a quieter ride.

Locking and Unlocking

Both the UnderCover Armor Flex, with its Dual Action Tailgate Seal, and the UnderCover Ultra Flex, equipped with slam latches and a dual-action latch at the tailgate.

They provide easy locking and unlocking mechanisms, allowing seamless tailgate access regardless of the cover’s position.

Both covers come with prop rods that allow them to stand at a 90-degree angle for complete bed access. However, this fully open position blocks the view.

For a partial opening, they can be set to a 2/3 position and secured with a strap, ensuring a rattle-free experience.


UnderCover Armor Flex with its LINE-X coating, the cover demands minimal maintenance, resisting common wear and tear. Simple wipe-downs should keep it looking fresh.

The sleek powder-coated finish of UnderCover Ultra Flex also ensures easy upkeep. The carpeted underside, while protecting against scratches, might need occasional vacuuming or brushing to remove debris.

Price Comparison

UnderCover Armor Flex comes in the price range between $1299 to $1349. It features sturdy aluminum panels and LINE-X coating which is used in boats and trailers.

Whereas UnderCover Ultra Flex has a price tag of $1199 to $1249. Its unique features are dual aluminum construction, L-shaped rails, built-in LED light, and carpeted underside.

From a cost perspective, the Ultra Flex is $100 less expensive than the Armor Flex, making it a more budget-friendly choice. Both have a 5-year warranty, so that’s a draw.

In terms of features, the Armor Flex shines with its LINE-X coating and textured finish, which might justify the extra cost for those valuing durability and aesthetics. Meanwhile, the Ultra Flex packs in utilities like the built-in LED and carpeted underside.

Both have justifiable prices because each cover comes with unique features. So it’s up to you now, what you need.

With UnderCover Ultra Flex, you’re saving 100 dollars and getting LED light in your truck bed and a carpeted underside. If you’re after the rugged durability that the LINE-X coating offers, the extra $100 for the Armor Flex might be a worthy investment.


In wrapping things up, after using both the UnderCover Armor Flex and Ultra Flex, I can vouch for their quality and functionality. The Armor Flex’s LINE-X coating is a gem, especially for those wanting a rugged touch. It is durable and requires very little maintenance.

The Ultra Flex, with its LED light and carpeted underside, feels like a luxury upgrade without breaking the bank. Ultimately, both are top-notch choices, but your decision should hinge on the specific features that align with your needs.

From my experience, either way, you’re in for a solid investment It comes down to your need, and which features you would prioritize.

2 thoughts on “UnderCover Armor Flex vs Ultra Flex”

    • Between the UnderCover Armor Flex and Ultra Flex, their water resistance capabilities are quite similar. Both use high-quality materials and designs to ensure effective water drainage and protection.

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