About Our Products: SUPERIOR QUALITY:Made of high quality Steel resisting corrosion and rust, ensure years of trouble-free use. EASY USAGE:Engine Barring Tool only insert the tool into the flywheel housing until it engages the ring gear, then attach a 1/2" square drive ratchet or breaker bar and turn. STRONG FUNCTION:Easy to rotate the engine and fit the flex plate teeth perfectly, the load-bearing collar provides friction-free operation while rotating the tool in the housing. Fit For: For Caterpillar(CAT) engines 3200/3406 series C13/C15/C16/3208/3400/3406e/3508/3512/3500 EUI/MUI engines,For Mack E7/E-7 ETEC Engine and so on. .