?Compatibility?Compatible for 4.000 inch bore including 6.0 LS2 LQ4 LQ9 L76 L77 L96 L98 and more 4.00" bore engines ?Function?By creating a slight squeeze on the piston ring the compressor eases the piston into the cylinder bore ?Easy Installation?Tapered ring compressor is an easy way to install without professional tools ?Product Material?Made of aluminum alloy 6061 material with easy-to-read laser etching ?Smooth Machined Surface?Smooth surface prevents piston rings from scraping against manufacturing tool marks