Fitment: Compatible with 1973-1987 Chevrolet C10 C20 C30 R20 R30 (Sierra, Heavy Half, High Sierra, Sierra Classic, Sierra Grande, Street Coupe); Compatible with 1973-1987 GMC C2500 C3500 R2500 R3500(Sierra, Heavy Half, High Sierra, Sierra Classic, Sierra Grande, Street Coupe) Material: High-quality steel with black powder-coat finish for corrosion resistance Function: Creates axle clearance for lowered ride height, reinforces the frame notch area, and repairs rust-damaged sections Installation: Bolt-on design using factory holes and included hardware; no welding or cutting required Package: Including 2 x c-notch and handwares as picture shown. Instructions not included