Rubber backer’s max velocity is 5000 RPM. Please NEVER se it with high speed grinder / polisher. (a) one 4 GB USB, it includes two video, one of it is “How to Fabricate Granite countertop DIY Undermount sink”, the other is How to Fabricate Granite Countertop DIY, Profile & Polish. (b) 39 Pieces of 4 Diamond Polishing Pad 3mm Thick, wet an dry use, wet use recommended. Grinder or polisher speed must be lower than 5000 RPM for granite marble concrete. 8 X Grit 50 100 200 400. 3 X Grit 800. 2 X Grit 1500 3000. (c) 1 Piece of 4 Diamond Professional Glaze Finishing buffer (it brings natural marble granite mirror like polished result). (d) 1 Piece of (5/8″-11 Female Thread arbor) 4″. (e) 3 Pieces of 4″ Diamond Turbo grinding cup wheel for stone concrete quartz travertine floor surface (5/8″-11 female Thread arbor). Cup wheel is random color: Red or Black. Recommend 2500 – 5000 rpm. Wet or dry use (wet use recommended).