CTA Tools 2020 Piston Ring Compressor Set installs piston rings from 2-7/8 to 4-3/8-inches / 73-111-millimeter. The 2020 includes ratcheting pliers and 6 sizes of 1-1/2-inches wide compressor bands. It works either parallel or perpendicular to the cylinder block. Whether tuning up your ‘68 Corvette or changing the oil on a John Deere tractor, CTA can supply you with the tools needed to do the job. California Prop 65