This is a decent folding tripod dolly, designed to give your tripod a bit of mobility on smooth floors. Nice in the studio or on set, and probably workable outside on pavement, too. The wheels are pretty decent 2" hard rubber casters with locks; the legs extend to accommodate most tripods. Folds up into an easy to carry little bundle (image shows it partially unfolded, it doesn't always look that weird.) In excellent condition.