A stair cleaning device intended for cleaning the steps and risers of stairs and other confined areas comprises {HEAD ~ three heads} driven by a motor and {TAIL ~ a belt and pulley system} 
driven by
A stair cleaning device intended for cleaning the steps and risers of stairs and other confined areas comprises { HEAD ~ three heads } driven by a motor and { TAIL ~ a belt and pulley system }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL