LSM Racing's universal heads-off heavy-duty valve spring compressors easily compress springs up to 1,000 lbs. Their frame and arms are machined from billet aluminum and their proprietary "Wave Beam" design makes them ultra-rigid and strong in a lightweight package. Their jaw capacity is 8 3/8 in. with a throat depth of 5 1/2 in., which provides enough clearance for even the hard-to-fit Big Chief and Hemi heads, and the spring cage's inside diameter can accommodate a retainer with an outside diameter of up to 1.650 in. The Acme lead screws on the valve and spring sides allow for compression from either end. Their unique removable handle reveals a 7/16 hex, which allows for a socket and battery-powered drill motor to be used to make big jobs quick and easy.