Bestop 42750-01  BestRail(TM) Channel Base Kit, 5.5-ft. bed 5.5-ft. Basic Channel Kit serves as modular base to mount BestRail tonneaus, racks and accessories Thick black anodized 6061-T6 aircraft grade aluminum for strength and scratch-resistance No-drill, bolt-together assembly with secure mechanical attachment system Can accommodate a BestRail tonneau, storage tub trays and ladder rack at the same time Fits truck beds 65" to 66-1/4"