This is a Grit Kit for a 20" Mirror. It contains the Grit and Pitch needed to grind and polish a mirror. It contains SiC #80 3 LB, #120 2 LB, #220 1 1/2 LB, #320 3/4 LB, WAO 25 Micron 1 LB, 15 3/4 LB, 9 3/4 LB, 5 3/4 LB, CEO 3 and Gugolz Pitch 6 LB.