Fully adjustable for safe use on stairways * Rugged 1 1/2 in. square tube steel frame unit * Includes four 29 in. W x 72 in. H precision-welded ladder end frames, 4 adjustable height side rails and two 67 in. L x 27 in. W plywood platforms with steel-reinforced edges for safety * Platform heights adjust in 2 in. increments for versatility * Eight double locking caster wheels with locking pins offer mobility