Snap-Loc E-Track Dolly – All-Terrain, 1,500 lb Capacity features 6” solid rubber swivel casters for smooth rolling on hard surfaces, dirt, gravel, grass, and most flooring, with brakes for control. Built-in E-Track anchors on all four sides allow cargo to be secured with E-Track straps (sold separately). Made in the USA from heavy-duty HDPE with a steel frame, this 3-in-1 modular system converts to a push cart and panel cart and interconnects for larger loads.