This pack carries (a)-(b). 3 Extra pairs of carbon brush included. Carbon brush is consumable parts of all types of polisher. Many other sellers DO NOT attach the lock ring. Remind: This polisher has no GFCI circuit breaker, our advice is plug this into a GFCI normally located in bathrooms and kitchens and using a extension cord from there. (b) 3 Pieces X 4 / 100mm Diamond Turbo Row Coarse Grinding cup wheel working layer velcro backed. Attach them to the aluminum pad holder to use for concrete and stone coarse grinding/polishing. 1 Piece of 4 aluminum pad holder / backer. Cup wheel color now is Red.