Pads can be wet or dry use (wet use recommended). This package (a)-(b). (a) 1 Piece of. Rubber Backing Pad 4″ Extra Flexible Backer Pad Hook Loop Backer 5/8″-11 Female Thread arbor. Remind: velcro backer’s max capacity / velocity is 5000RPM, please don’t use it with high speed polisher/grinder. Description: Super flexible rubber backer pad are designed for connecting polishing tool and polishing pads. It is thin and super flexible, more suitable for polishing edges. The connection is 5/8-11 Female Thread. We use top quality Hook and Loop Self adhesive. It will not peel off. (b) 48 Pieces of 4 / 100MM Diameter Pad for granite marble concrete travertine they can be wet or dry use. Wet use make its life longer. 16 Pieces of STEP 1, STEP 2, STEP 3. Recommend 2800 – 5000 rpm (grinder or polisher speed must be lower than 5000 RPM). Wet or dry use (wet use recommended).