^_. Used to remove bulit-up carbon from the piston ring grooves  

^_. Easy two-hand operation, fit all grooves.  

^_. Spring-loaded for fast cleaning.Handles pistons 2-3/4''to 5''dia(69.8-127mm)  

^_. Comes with standard cutter sizes5/64'',3/32'',1/8''.5/32''3/16''.>Also special cutter sizes 1.5mm,2mm and 1/4''