Hammer tight spanner to fit nearly all post war motors. A very useful tool for tightening and loosening flywheels. Also it can be used in conjunction with C9362 to undo very tight clutches. fits 6E 7E 8E 9E 10E 8D 9D 10D 11D 12D 13D 24C 25C 29C 30C 31C 31A 32A 33A 34A 36A 37A and many more motors. A very usefull tool.