Abstract: An attachment for use on a rotary floor conditioning machine comprising a master block which is integrally molded of a urethane elastomer including a centrally located hub with a circular flange member extending radially from the base thereof. A plurality of spaced vertically extending tubular receivers are carried on the circular flange. An integrally molded attachment made of urethane elastomer is provided for being attached to the master block through vertically extending posts. Stiff bristles extend out the lower surfaces of the attachment plate. The attachment plate may be molded in two stages so as to produce a stiff upper layer and a more flexible lower layer.