Giantex Hd 4 PCS Set Tire Wheel Dollies Dolly Vehicle Car Auto Repair Moving Diamond Heavy Duty Steel- We use top grade steel. Super strong quality with stable structure makes large load capacity up to 1,000 lbs each. Smooth Wheels for Easy Operation- Smooth universal wheel makes it easy to operate on rough and smooth surfaces Safety Rails and Handle- Each dolly has double side safety rails to keep tire in place when moving. It also can be used as a handle for easy carrying and storage (hanging available). "U" Shape Design- Allows for greater stability and versatility in moving cars, boats, trailers, etc. Perfectly fits to almost anything round or cylindrical. Functional and Suitable For Multiple Places- Ideal for places like garage, auto sales showrooms, workshop, parks etc.