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2021 GMC Sierra 2500/3500HD Fender Flares & Tonneau Covers

Are you ready to protect your '21 Sierra Heavy Duty SLT pickup with some off-road fender flares? We've got the selection for you. Fender flares for the 2021 GMC Sierra HD Denali are easy to install and do not require any modifications or drilling into your Sierra AT4 double cab or crew cab truck. Whether you're looking for the off-road, bolt-on style or a more simple, sleek OE factory style flare, RDJ Trucks has the what you're looking for. All fender flare products come in complete sets of 4 with all necessary hardware and installation instructions. At RDJ, we only sell what we use on our very own trucks!





RDJ TRUCKS FENDER FLARE STYLES for your 2021 GMC Sierra 2500/3500HD Pickup

PRO-X-TEND DLX
Made in the USA! A premium quality, American made, maximum coverage fender flare with a sleek, clean look for your premium GMC Sierra HD.

PRO-OFFROAD
A maximum coverage fender flare with a bolt-on, riveted style. The most popular design on the road today.

PRO-X-TEND
A maximum coverage fender flare with a sleek, clean look. A more original appearance rather than the added-on look.

HWY-PRO
A slim profile with an OE/factory flare appearance. An understated, functional design intended for on-highway protection.


RDJ TRUCKS FENDER FLARE FINISHES for your 2021 GMC Sierra AT4, Denali, SLT, etc

SMOOTH PAINTABLE // Limited Lifetime Warranty
A matte black, smooth surface that can be left as-is or can be painted to match the color of your truck

TEXTURED BLACK // Limited Lifetime Warranty
An matte black, aggressive textured surface that provides an amped-up look to your pickup

*NEW* SMOOTH w/RHINO SKIN // Limited Lifetime Warranty
Our smooth surface sprayed in RHINO SKIN, a scuff and fade resistant bedliner type of coating, for the ultimate rugged protection for your fenders

*NEW* TEXTURED w/RHINO SKIN // Limited Lifetime Warranty
Our aggressive textured surface sprayed in RHINO SKIN, a scuff and fade resistant bedliner type of coating, for the ultimate rugged protection for your fenders

PAINTED TO MATCH // Lifetime Limited Warranty
Your fender flares painted to match the color of your GMC. High quality PPG automotive paints, mixed and applied to factory specifications


RDJ TRUCKS TONNEAU COVER STYLES for your 2021 GMC Sierra 2500/3500HD Crew Cab or Double Cab

TRAVEL-PRO 65-SERIES HARD TRI-FOLD
A premium all aluminum hard tri-folding tonneau cover to protect your valuable load. Super easy to install and remove. Protect anything you haul in your 2021 Sierra heavy duty truck bed.