DOUBLE SEGMENTS - diamond encrusted bar segments EXTRA SOFT BOND - suitable for grinding hard to very hard concrete GRIT SIZE & SET - #18/20 grit size includes 3 grinding discs USE WET OR DRY - walkbehind grinder recommended COMPATIBLE - fits Husqvarna PG 280/400/450/530/680/680RC/820/820RC Grinders Diamond grinding tooling designed for Husqvarna PG series floor grinding machines. 3 piece set with extra soft bond which is ideal for very hard concrete or very high speed concrete grinding. #18/20 grit with 2 diamond segments, use wet or dry with Husqvarna floor grinders such as PG 280/400/450/530/540/680/820/830.