Casters take your light stands mobile! They especially come in handy when you are doing work in the studio. Casters will protect your floors, keep things quiet on set and of course, make repositioning your lighting fixtures that much easier. The KS940612 is a set of three 3-15/16" (100mm) casters designed to fit 3/16" (30mm) square legs. This set of casters has brakes that prevent the wheels from rolling and keeps your stand locked in place.