GM-50717 is an alternative to MKM-6086 for GMNA dealers (and other global regions that don't already have MKM-6086) to allow valve spring and seal service on current Family 0 (1.4L) and Family 1 (1.6L, 1.8L) engines, and on upcoming LGE (Ecotec Gen II) and SGE gasoline, and VM Motori diesel engines. GM-50717 has adjustable end brackets that bolt to the head, with bars between them to center the compressor assembly over the valve. The compressor assembly can also be used with the existing GM-8062 Valve Spring Compressor with the head removed. Can be used on or off the vehicle.