Check the listing for details. 66784 Stud Mount Valve Spring Compressor Tool For all 3/8" & 7/16" Rocker Studs. Condition: New. Listed at 45.98 USD. 66784 Stud Mount Valve Spring Compressor Tool For all 3/8" & 7/16" Rocker StudsFitment:For all 3/8" & 7/16" Rocker Studs. Specially designed for compressing valve springs with the cylinder head on block Features: 1) Easily and quickly remove valve spring from an assembled engine for checking or replacing 2) Handle swivels 360 degrees to compress and lock spring down to desired height and remove handle while removing or installing keepers. Press down to compress coil spring, then remove valve keepers. Release slowly 3) Crafted from heavy-duty steel for professional level reliability and durability, a zinc plating for added corrosion protection, providing a long-term service. Rubber grip handle for anti-slip and labor-saving Package included: 1x 66784 Stud Mount Valve Spring Compressor