For safe and quick installation of piston rings by simple ring expansion, use the ABN Adjustable Piston Installer Pliers – Piston Ring Spreader – Expander Plier Tool for Installation 3/64” to 1/4" Inch. These pliers expand or spread rings to insert into the groove and install on a piston. The tool is designed for use on the most common piston and ring diameters ranging in thickness from 3/64-inch to 1/4-inch (1.2mm to 6.4mm). It is constructed from all steel with tapered jaws and vinyl-coated handles with nonslip rubber grips that offer safe and comfortable operation for less user fatigue and more productivity. Not intended for compressing piston rings. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.