1. Allows for the smooth tracking of a tripod or stand for a camera, microphone, etc. Can be set up in a wheel only situation, or with a track which the wheels rest on for predefined movement.
2. Specifically, caster assembly for a grand piano.
http://www.vandaking.com/jansen-grand-piano-truck-dolly-do-j-6542.html
2. Specifically, caster assembly for a grand piano.
http://www.vandaking.com/jansen-grand-piano-truck-dolly-do-j-6542.html