UnderCover Flex vs Ultra Flex Bed Cover Comparison

Updated on May 5, 2025

RealTruck Expert Team
Written by
 RealTruck Expert Team
Frank Bisciotti
Edited by Frank Bisciotti
Top view of a dark-colored pickup truck with a closed tonneau cover on the bed.

UnderCover brings us the Flex and Ultra Flex tonneau covers. Both have many benefits that vary depending on utility. Our comparison will help you decide which cover best fits your lifestyle.

Shared Features

Lock icon with "Secure" label indicating security or safety.

Secure Locks with your truck's tailgate lock.

Water-resistant icon with drops, labeled "Water Resistant."

Water Resistant Seals around the bed to prevent most water from entering.

Icon of a shoe and a belt with the text "Accessories Compatible" underneath.

Accessories Compatible Works with wheel well tool boxes and cargo dividers.

Tools icon with "Easy Installation" text below.

Easy Installation No drilling required.

"Made in the USA" label with small American flag icon.

Made in the USA American-made quality.

UnderCover Flex

UnderCover Ultra Flex

Open truck bed with a black tonneau cover raised.

Under Panel Material

Panel undersides are textured FRP (fiberglass reinforced polymer).

Open truck bed with a fold-up tonneau cover secured by support cables.

Under Panel Material

Panel undersides are lined with a carpet-like material to protect valuables against damage like scratches, dents, and dings.

Red pickup truck with kayak and second truck parked near a riverbank.

Low-Profile Design

Flush with bed rails, this cover doesn't affect gas mileage.

Part of a pickup truck bed with a closed tonneau cover near a lake and trees.

Ultra Low Profile

Adds sleek styling without affecting gas mileage.

Rear view of a white Chevrolet Silverado pickup truck with a closed truck bed cover.

300 Lb Weight Capacity

Holds up to 300 pounds of evenly-distributed weight.

Open truck bed with tonneau cover lifted, showing cargo area of a Ford F-150.

400 LB Weight Capacity

Holds up to 400 pounds of evenly-distributed weight.

Girl and boy loading backpacks into a red pickup truck's tailgate.

Three-Year Warranty

The Flex is backed by a three-year warranty against defects in materials and workmanship.

Open truck bed with a cover, overlooking a lake and green landscape.

Five-Year Warranty

The Ultra Flex is backed by a five-year warranty against defects in materials and workmanship.

Person loading a red kayak into the back of a white pickup truck by a river.

Other Accessories

The Flex does not come with any additional products.

View Product

UnderCover Flex Tonneau Cover Product Review (01:14)

UnderCover Ultra Flex tonneau cover product review (01:56)

If you need help measuring your truck bed, check out our helpful article or contact our product experts.

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