Keep multimeters, oscilloscopes, and other instruments at a convenient viewing angle and height. The top shelf has 1-1/4" high lipped sides and a guardrail with rubber bumpers to prevent items from slipping off. The bottom shelf is flush. Shelves are plastic-coated composite wood for easy cleaning. Four swivel casters make these carts easy to maneuver. Their rubber tread-on-core wheels have a hard core for strength surrounded by a shock- and sound-absorbing tread for a cushioned ride on all surfaces.