POWERTEC 17200 Retractable Caster Kit (4 Pack) Fits most open steel stands with 12.5 degree angled legs (will not work properly with straight or vertical legs); For straight, vertical legs refer to POWERTEC models 17000 or 17001 (Retractable Caster Kits) Designed to maintain original stand height Durable steel construction can move up to 600 lbs 4 freely pivoting, 2- inch diameter polypropylene ball casters Simple, innovative foot pedal mechanism; mounting screws included for easy installation