S-4-1 Specifications (Dimensions in inches, weight in pounds) Width, overall 20 Length, overall 45 Height, overall 50 Height, top step 30 Height, top shelf 38 Average max, eye level 90 Shelf, top 19 1/2 x 31 1/2 Shelf, center 19 1/2 x 31 1/2 Shelf, bottom 19 1/2 x 39 1/2 Flange clearance (between shelves) 13 1/2 Steps 4 3/4 x 17 Net weight 68 Shipping weight (estimated) 78 Load capacity, load at rest 500 List Price (Call for dealer information) Pricing (any shelf capable of bearing total load capacity) Material-satin-finish aluminum, 1/8" sheet and 3/4" IPS pipe. Casters-5", corner-mounted, 2 fixed, 2 swivel on ladder end.