A clutch is a mechanical device that engages and disengages power transmission. In the simplest application, clutches connect and disconnect two rotating shafts drive shafts or line shafts. The clutch connects the two shafts so they may be locked together and spin at the same speed engaged, locked together but spinning at different speeds slipping, or unlocked and spinning at different speeds disengaged. Specifications. Height 1.15 in.. Width 2.8 in.. Length 2.5 in.