Login
My Account
My Cart
The site navigation utilizes arrow, enter, escape, and space bar key commands. Left and right arrows move across top level links and expand / close menus in sub levels. Up and Down arrows will open main level menus and toggle through sub tier links. Enter and space open menus and escape closes them as well. Tab will move on to the next part of the site rather than go through menu items.
Enter your truck info so we can recommend the right products for you.
Can't find it? Call us at 859-737-4966 for free advice.
Menu
Air Filters
Air Intakes
Clutches
Cooling System
Drive Line
Electronics
Engine
Engine Parts
Exhaust
Exhaust Brakes
Fabrication Components
Fluids
Fuel Systems
Fuel Tanks
Gauges
Injection Pumps
Injectors & Related Items
Intake Manifolds
Intercoolers
Lift Pumps
Programmers
Silicone Hoses
Suspension
Tools
Transmissions
Turbochargers
Water Meth Inj Kits
Thoroughbred Diesel has been your online performance headquarters since 2002. We know how to get the most performance out of your pickup truck and offer all of today's most popular diesel performance products.
Brakes
ECM
Electrical Components
Engine Components
Exterior Replacement Parts
Filters
Fuel Pumps
Gaskets & Seals
Interior Replacement Parts
Oil Pumps
Starters & Alternators
Thoroughbred Diesel offers OEM and diesel stock parts for your diesel pickup truck. At Thoroughbred Diesel, you can buy stock diesel replacement parts such as injectors, fuel pumps, ball joints, track bars, turbos, and more for your diesel truck.
Injection Pump
Injector
Turbo Charger
Batteries
Bed Covers
Bumpers
Fender Flares
Floor Mats and Liners
Grilles
Horns
Lighting
Mud Flaps
Nerf Bars
Running Boards
Seats & Covers
Shift Knobs
Spare Tire Carriers
Storage
Tailgate Nets
Tool Box
Truck Steps
Ventvisors
Wheels
Winches
Make heads turn with custom truck accessories from Thoroughbred Diesel.
Ball Mounts
Gooseneck & Fifth Wheel
Hitch Balls
Hitch Pins & Hitch Locks
Hitch Steps
Hitches
Loading Ramps
Shackles & Tow Hooks
Tow Brakes
Tow Mirrors
Towing Accessories
Weight Distributing Hitchs
Banners
Decals
Hats
Hoodies
License Plates
Shirts
Tank Tops
Show your support with a Thoroughbred Diesel t-shirt, sweatshirt, or sticker decal.
Thoroughbred Sku #: UNDUX12026 Manufacturer Sku #: UX12026
Year/Make/Model: {{year}} {{make.Name}} {{model.Name}} Edit
$1,399.99
2020 - 2021 GMC Sierra 2500
2020 - 2021 GMC Sierra 3500
2022 - 2022 GMC 2500
2022 - 2022 GMC 3500
2023 - 2024 GMC Sierra 2500 HD
2023 - 2024 GMC Sierra 3500 HD
Product Name:UnderCover Ultra Flex Tonneau Cover 2020-2024 GM Sierra 2500/3500 HD 8.2ft Bed Manufacturer: Undercover Manufacturer Part #: UX12026 Thoroughbred Diesel Part #: UNDUX12026 Fitment Notes: 2020-2024 GM Sierra 2500/3500 HD 8.2ft Bed
A hard folding truck bed cover that comes with overwhelming new features and is topped off with an alluring matte finish. The Ultra Flex is in a category of its own. From the irresistible outward appearance to each component beneath the cover, the Ultra Flex has been carefully crafted to be the ultimate all-purpose truck bed cover.
All-new features that accompany the Ultra Flex include an integrated luminous rail light system for enhanced night vision, and a dual action tailgate seal, allowing for easy operation and you to close the tailgate with the cover-up or down. Multiple riding positions allow the user to ride with full access to their bed, and full weather protection is available if the cover is in the fully closed position.
Ultra Flex is an easy clamp-on application and can be installed and removed easily with Undercovers newly designed L-Rail’s. The Ultra Flex is backed by a 5-year warranty, making it the most desirable folding cover on the market.
UnderCover Ultra Flex Tonneau Cover Features: