Description:-This tool is designed to be used with or without the heads on the engine. You can use a pneumatic air fitting to put compressed air in the cylinder to hold the valves closed when using.Specification:1. Type: Valve spring compressor Tool Kit2. 100% Brand new and high quality3. All units tested in excellent working condition4. Easy installationFitment:-For Chevy LS1 LS2 LS3 LSX 4.8 5.3 5.7 6.0 LS-It will work on any LS engine for Firebird, for Silverado, for Camaro, for GTO, for Trans am, for Corvette, for CTSV, for Sierra, for Tahoe, for Suburban, for Pontiac G8 GT and more trucks-Extreme Grade High Quality Bolts and nuts for durability!-Precision CNC Machined, Our Valve Spring tool is a great alternative to the higher priced tools and does the same Job!-Our tool is built from 3/8" Steel and CNC machined for a great fit and Durability.-Warning: Always use Eye protection when changing Valve springs!   Package Included:1X Valve Spring Compressor Tool Set(Stud. Nut. Valve Spring Compressor)