Item Name: Rear Engine Covers to centered Rear Cover Billet Alignment Tool Alignment Tools. Align the seals perfectly concentric to the front diameter on the balancer hub and rear sealing surface on for proper seal function and longevity.Simple yet powerful.100% Brand New and High Quality !Function: Used to align the rear cover so that the rear main seal is centered when installed.Easy installation with this tool, saving your time and energy !Size:As the picture shownMaterial:Billet aluminum & Quality steelFits for LS Series Engines 4.8 5.3 5.7 6.0 for LS1 for LS2 for LS3 for LS6 for L99 for LS9 for LSA for LQ4Package Include:1PC Rear Cover Billet Alignment ToolNote:1.Please allow 1-2cm error due to manual measurement.