Fitment: The included six innovative bands can be tightened to fit for car engines with piston diameters from 2-7/8” (73mm) to 4-3/8” (111mm). Versatile for multiple vehicle applications, a must-have tool kit for professional mechanics and DIY enthusiasts alike Features: 1) Specially designed to easily & properly install the piston ring into the cylinder, safely compress it in place without twisting or damaging parts, ensures a smooth installation process and makes the job breeze, saving your time, energy and money .