Piston Ring End Gap ToolCaracteristicas: This tool makes measuring ring end gap faster, more accurate and eliminate the guess work Flanged design allows piston ring to fit squarely in cylinder bore every time Just install any ring, top, 2nd, or oil control rails on the tool Install tool into a cylinder bore and then view the ring end gap in the Key Slot Use a feeler gauge to get your end gap measurement Each side of the tool is made for checking a standard size piston rings