Charger Plus Series employs blend of zirconia alumina and aluminum oxide. Type 27 1/8 in. and 1/4 in. thick grinding and cutting wheel is available in 4, 4 1/2, 5, 6, 7, and 9 in. dia with both 7/8 and 5/8-11 center holes. Type 28 saucer wheel is available in 7 and 9 in. dia, 1/4 in. thickness with 5/8-11 center holes.