The router bit and pad holder’s arbor is 5/8-11 Female Thread. Pad Holder’s max velocity / capacity is 5000 RPM. Please do not use it with high speed grinder or polisher. This package carries (a)-(c). (a) 1 Piece of V20 (20mm / 3/4 Inch). Full Bullnose for 20MM (3/4″) THICK / HIGH STONE CONCRETE Diamond Brazed Router Bit/Profiler for 20mm (3/4″) stone concrete travertine to do Full shape bullnose (5/8-11 Female Thread arbor). (b) 1 Piece of V30 (30mm / 1-1/4 Inch). Full Bullnose for 30MM (1-1/4″) THICK / HIGH STONE CONCRETE travertine to do Full shape bullnose (5/8″-11 Female Thread arbor). (c) 16 Pieces of 4 / 4 Inch / 100 mm. Diamond PREMIUM GRADE DRY Polishing Pad for granite marble concrete. 3 X Grit 50 100 200 400. 1 X Grit 800 1500 3000 Buff. And 1 Piece of 4″ / 4 Inch / 100 mm Velcro Backer/Pad Holder (5/8″-11 Female Thread arbor). VERY IMPORTANT REMIND: Velcro Backer’s max velocity / capacity is 5000 RPM. Please don’t use it with high speed grinder/polisher. Please don’t use with high speed grinder/polisher. With water feed hole, can be wet use.