Original Rough Roller Electric Rough Roller Rough Roller II Easy Assembly The custom patented "Ball / Re-Invented Wheel" will float on very deep snow and sand. It acts opposite of a normal caster wheel, on a standard wheelchair, and ALL manual "off road" wheelchairs made today. Quadriplegics and all others will love it because it will adapt in seconds to ANY electric wheelchair. The Rough Roller II is a less aggressive "dual ball" front caster design with independent suspension. This allows for greater mobility in tight spaces but still offers excellent mobility on hard to navigate surfaces. Quick release technology makes assembly of Rough Roller products a snap.