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