A must have for on-the-spot caster replacement. This unique tool can remove, measure and install casters quickly and easily with no damage to casters, chairs or your hands. Pop out any grip ring stem caster with one quick snap, loosen or tighten threaded stem casters with a simple twist, and measure stem diameters of the most common sizes, even metric. Comes complete with a Selector Slide for caster wheel identification, simple instructions and a poly-vinyl carrying bag. Many new chairs are equipped with hard wheel casters for use on carpeted surfaces only. Hard wheels skate and slide on hard floor surfaces. For safe rolling on all hard floor surfaces, including chair mats, soft wheel casters should be used. Soft wheels provide traction and prevent skating, sliding and run-away chairs.