Black: stripping & cleaning. For wet scrubbing strong layers of emulsion floor polishes. For machines operating up to 600rpm. 85mm push out centre hole prevents the floor pad from overheating. Pads hug uneven floors and can be used on both sides with no loss of efficiency. To extend the life of the pads, brush the pad surface while rinsing with clean water by using the centre push-out piece, and hang to dry.