Constructed of high density polyethylene with steel reinforcement for rigid support and strength. Trays have a 40 lb. Load capacity and stack up to 5 feet high. White finish. Stack trays are packed 2 per carton. Model 4897 - Dimensions: 36 1/4"W x 24 1/4"D x 2"H. Model 4899 - Dimensions: 42 1/4"W x 32 1/4"D x 2"H.