Pad driver block fits most rotary floor machines. Unevenly trimmed, 1/2-inch poly nodules ensure secure scrub pad attachment. Pre-installed clutch plate. Durable plastic block and riser. 20-inch block. HUB Compliance: N/A; Compliance, Standards: N/A; Pre-Consumer Recycled Content Percent: 0 %; Post-Consumer Recycled Content Percent: 0 %. Includes pad driver block and clutch plate.