The Miller 481 Studio Dolly with Cable Guards for Sprinter and HD Tripods boasts adjustable cable guards for smoothing out studio floor litter, plus a reinforced centre hub with collapsible box tubing arms. Smooth action castors ensures the 481 Studio Dolly, to run smoothly and surely under all ENG, EFP and HD tripods.Height Adjustable Cable Guards Reinforced centre hub Collapsible arm design Sturdy Tente roller castors .