Pads can be wet or dry use (wet use recommended). Very flexible rubber backer’s max velocity / capacity is 5000 RPM. Please do not use it with high speed grinder or polisher. This package (a)-(b). (a) 1 Piece of. Aluminum 5″ backing pad 5/8″-11 Female Thread arbor. (b) 1 Piece of. Rubber Backing Pad 5″ 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) 26 Pieces of 5 / 125MM Diameter Pad for granite marble concrete travertine they can be wet or dry use. Wet use make its life longer. 5 X Grit 50 100 200 400. 2 X Grit 800 1500. 1 X Grit 3000 10000. Recommend 2800 – 5000 rpm (grinder or polisher speed must be lower than 5000 RPM). Wet or dry use (wet use recommended).