This is an OEM type LEFT & RIGHT
Rocker panel & inner rocker panel set for your
73-87 Chevy GMC Truck
73-91 Chevy GMC Blazer/Jimmy
73-91 Chevy GMC Suburban

Fits regular cab, blazer, suburban & crew cab (front only)

Outer rocker measures about 47" x 4"
Inner rocker measures about 30" x 4"

If your rocker is rusted enough a "slip-on" style will not cover you Then this is the panel you need.....!

Left = Drivers side
Right = passengers side