ShineMate 3 inch Vented DA backing Plate, 5/16” x 24 thread, common for most short-throw polishers.
Multi-hole backing plate to keep the temperature down when polishing, a must for hot dry summer days. If and when the heat builds up too much while polishing, it can soften the glue and the hook and loop surface and delamination may occur. Excess heat can also cause the foam structure to collapse and disintegrate over time.
For the typical Porter Cable, Griot's G8, G9, Shinemate ERO600, Adam's Mini 3" etc polishers.