The Cornwell Bone Rough Rider Creeper can be used on dirt, rough pavement and gravel with a firm substrate. With a capacity of 400 lbs, this creeper has a ground clearance of 2-7/8". It is 45-1/2" long by 25-1/2" wide by 7-7/8" high and weighs 20 lbs. The wheels are 5-5/16". This product is made in the U.S.A and comes with a lifetime warranty.