From the manufacturer
Harper Trucks Convertible Hand Truck and Dolly
The Harper Trucks nylon truss frame is 30% lighter than steel and designed for maximum strength. This hand truck has a 300-pound vertical capacity and 400-pound platform capacity.
The hand truck easily converts in seconds from 2 wheel dolly into 4 wheel cart to fit the needs of any project. The 8-inch wheels have solid rubber tread and 3-inch swivel casters. The built-in stair glides for easy moving up or down stairs and curbs.