A-B1843822-AI RING SET-020One New Aftermarket Replacement Piston Ring Set (. 020 Oversize) Fits Briggs and Stratton Small Engines This aftermarket replacement piston ring set is a . 020 inch oversize set designed for use in Fits Briggs and Stratton (Fits Briggs and Stratton) small engines that have been bored . 020 oversize during cylinder reconditioning. The piston rings seal the gap between the piston and cylinder wall, separating the combustion chamber from the crankcase to