2in.-thick top shelf is molded with steel reinforcements for extra strength. These handy Computer Workstations feature thick shelves with a textured surface, which helps to prevent papers from sliding off. Plus, the 1/4in. retaining lip keeps liquids and writing instruments from spilling onto the floor. Rugged thermoplastic material endures frequent use. Shelves are designed to stay in shape - material won't chip, warp, rust, crack or peel. Silent-roll, full-swivel casters (2 locking) for easy mobility.