Quadraspire Casters are wheels you can add to any Quadraspire feet. You unscrew the foots spike or rubber footer and screw on the caster. See photo titled "Foot & Caster".
A particularly nice use of these is on Quadraspire Amplifier stands. We have several Quadraspire Q4 and SVT amplifier stands in the store and have casters on many of them. If you like to move different amplifiers in/out of your system this is a terrific aid.