Technical role and importance of piston rings The original set of piston rings for STIHL petrol trimmers, 32 mm in diameter and 1.5 mm thick, plays a key role in maintaining optimal compression pressure inside the cylinder and preventing gases from passing into the crankcase. They are made of special cast iron with high wear resistance, developed to work under extreme thermal and mechanical loads in demanding operating conditions. The 1.5 mm construction significantly reduces surface friction and wear of the assembly, which directly contributes to stable revolutions and extends the working life of the engines of professional machines. Key characteristics Part type: Piston ring set Catalogue number: 4112 034 3000 Installation position: Grooves on the engine piston (32 mm bore) Function: Maintaining compression and sealing the chamber Material: Hardened cast steel with a chromed layer Unit of measure: Set (2 pieces) Compatible models Petrol trimmers STIHL FS 80 E / FS 80 RE STIHL FS 80 AVE / FS 80 AVRE STIHL FS 81 / FS 86 Before fitting a new ring, be sure to thoroughly clean the groove on the piston of burnt oil residue and soot. The ring material is brittle, so fit it carefully and without excessive spreading so that it does not break. Call us to check stock in Subotica.