Bakflip MX4 vs Undercover Ultra Flex

Both of these products are tri-fold tonneau models that give you the flexibility to drive with a fully open, partially open or completely covered truck bed. The robust aluminium cores make these fittings durable and also provide the facility to load cargo over the cover. Plus, dual-action tailgate seals allow the tailgate and tonneau to function independently of each other. Likewise, easy installation and long warranties further add to the benefits list.

The Bakflip MX4 is a hard folding cover made of lightweight aluminium panels. All its parts (rails, clamps, and elevator bolts) have a matte black finish leaving no part of metal exposed to air or moisture, providing the benefit of durability and corrosion resistance. Besides that, the enhanced rubber of lengthwise seals and bumpers along with sturdy prop rods further improve its functionality.

Ultra Flex also gives a matte black outlook with three folding panels. Its powdered finishing protects it against UV damages, temperature corroding and wear and tear due to dust microparticles. The feature that gives it an edge over the competitor is the carpeting of the lower side of the panels, making both of its sides long-lasting. Also, the integration of LEDs in rails makes it more user-friendly in comparison.

In comparison, MX4 has enhanced rubber seals, shock absorptive bumpers, durable prop rods and rail LEDs while Ultra Flex has wear-resistive panels. However, drainage efficiency, warranty and price ranges are the same for these tonneau covers.

Quick Comparison Table

ExteriorMatte Black finishMatte Black finish
RetractionHard foldingHard folding
SecurityDual Action tailgate sealDual Action tailgate seal
Weight Bearing Capacity400 lbs400 lbs
Remote PoweredNoNo
Warranty5 years5 years
Price$971.89 – $1,026.79$971.10 – $1,079.10


MX4 is an ultra-low profile cover for your truck bed with a smooth, matte black finish. It has three hard folding panels and covers the full length of the bed when unfolded. It needs to be operated manually and can be fixed in completely closed, partially opened and fully folded forms. Each panel has slam latches and gets automatically fixed as you unfold it. Dual-action seal makes the tonneau cover and tailgate independently functional; both can be used without opening the other.

Ultra Flex resembles the contestant design-wise as it is also a tri-fold, matte black, hard folding tonneau cover. It also can be used at three secure positions and has a dual action tailgate seal. However, it has LED lights integrated into its rails, providing a benefit in low-light weather and night trips.

FinishingMatte Black finishMatte black, powder coat finish
RetractionHard foldingHard folding

Composition and Protection

MX4 is constructed from lightweight Aluminium panels which are protected with a UV resistant matte black covering. Its aircraft-graded metal slats make it physically robust. UV protective layer helps it face the scorching sunlight especially when you take your truck off-road in a dry climate. Plus, there is a full-fledged water drainage system.

Ultra Flex has Aluminium sheets in its panel core and an Aluminium skin on the top. The outer layer is created by a powdered coating of UV resistant matte black polymer. This layering makes it resilient to high-temperature damages, fading and buckling. Besides that, its panels are carpeted from underneath which creates a cushioning effect and save the tonneau from scratches, chips and cuts. Its drainage system is very similar to the competitor

CoreAluminium panelsAluminium panels
UV protectionYesYes


Ultra Flex shows an optimized tonneau performance; it saves truck beds from rainwater and dust, offering a sound hauling facility. It can withstand a top-load of up to 400 pounds evenly balanced on the closed cover. Tough aluminium panels keep the bed protected from dust, rain and snow. An efficient drain system is integrated with this cover in which built-in drainage tubes are present in rails to automatically channel water outwards, keeping the bed and stored cargo completely dry. Also, there are lengthwise and hinge seals to prevent any leakage of moisture. You can also have full-bed and partial access with this cover as it can be locked in 2/3rd open position as well as at 90° for complete access.

MX4 matches with its competitor for its performance due to identical design features. As its weight-bearing capacity is also 400 Ibs, it comes at par for hauling efficiency. Likewise, it allows you to use complete or partial truck bed space just like its competitor. Its drain system is also identically designed yet it has an edge over the contestant due to enhanced seal rubber and completely covered rails. Its EPDM rubber seals are comparatively more water-resistant; thus, its end caps show a higher proficiency in preventing water from trickling onto the truck bed. Plus, its rails are corrosion resistant as no portion exposes raw aluminium to draining water.

Operating StyleManual foldingManual folding
Remote controllingNoNo
Seal compositionEPDM rubber + polymer enhancementsEPDM rubber


Though these products do not come with a key-enabled lock facility, these are completely secured when properly installed. Both covers employ dual-action tailgate seals. Hence, you can lock the tonneau in place both with an opened or closed tailgate. Similarly, both truck accessories integrate slam latches and a “pull the string” opening system. The lock can be opened from either side of the cover, just pull the latch string and fold the cover in the backward direction to access the truck bed. You can either fold two panels and secure the tonneau with an in-built strap to drive with 1/3rd covering or fold all panels and fix the cover with prop rods to get full bed access.

Despite the same latch system, MX4 gets a higher score for security as its pre-moulded, die-cut bumpers act as shock absorbers protecting the tailgate when closed. These bumpers also provide a cushion for the cab’s surface when fixed on struts but this does not completely eliminate the risk of scratches. It also has the advantage of relatively robust prop rods, enabling you to accelerate up to highway speeds without any concern when the driving with a completely folded tonneau cover.

In contrast, bumpers of Ultra Flex have relatively less shock absorptive quality and its prop rods are also relatively less durable. But this cover stands at 90° when fully folded and does not touch the surface of the cab. Thus, there is no chance of scratches due to surface rubbing.

Latch systemslam latchesslam latches
Latch points33
Partial accessYesYes


Aluminium cores make these truck bed covers mechanically sturdy; thus, they endure jolts and weight pressure very effectively. Plus, UV resistive coverings prevent damage from heat and ultraviolet radiations, making the covers weather resistant as well. Resultantly, these products last for long durations. That is why these are backed by manufacturer warranties for up to 5 years.

Tough comparatively speaking, we can say that MX4 will last longer because the finishing of all components and composition enhancement of seals, bumpers and struts makes it more durable than the competitor.

Conversely, panel construction of Undercover is better as its outer side has UV resistant coating and the lower side is carpeted to reduce chips and cut damage. Nevertheless, lesser protective features for other components reduce its longevity.

Quick Summary

  • Both of these are tri-panel hard folding tonneau covers.
  • Both are UV-resistant, matte black truck accessories.
  • Both covers can be installed easily without drilling.
  • Both tonneau covers have the same weight-bearing capacity.
  • Latch methods and water drainage systems are similar for both fittings.
  • Both accessories have the same warranty from their manufacturers.

Undercover Ultra Flex

  • Has a powdered matte finish over the outer layer.
  • Contains built-in LEDs in rails to make operation easier in low light.

Bakflip MX4

  • Has more efficient rubber seals than the competitor.
  • Has relatively sturdy, durable prop rods and shock absorptive bumpers