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