Eastwood Die Grinder Kit with 16pc Accessory Set. This air powered mini grinder kit includes 16 total pieces. One die grinder, two collet wrenches, one 1/8 inch collet, one 1/4 inch collet, five 1/8 inch grinding stones, five 1/4 inch grinding stones, one 1/4 inch NPT air inlet coupling, and one storage case. The die grinder has a max free speed of 22000 rpm. This tool uses 4.5 cfm at 90psi.