In car valve spring changes have never been easier for the home hot rodder. This valve spring compression tool works on C6, C5, F Bodies and all LS1 powered vehicles. The main body is made of billet aluminum and incorporates a steel roller bearing trunion for ease of operation. This tool is designed to work with any 3/8 hand ratchet, simply add a 3/8 extension for valve springs which are difficult to reach (under cowl). Will work on factory conical valve spring along with aftermarket 1.25 OD spring/retainer sets. For anyone changing camshafts with more than .500 valve lift , this tool is a must. Not suggested to be used to change springs with the engine in the car for 5 Gen Camaro LS3.