Check the listing for details. Hyway POP UP piston kit for Stihl MS461 52mm + Caber rings extra compression. Condition: New. Listed at 44.99 USD. Brand new Hyway POP UP extra compression piston kit. Fits Stihl chainsaw model MS461, standard 52mm bore size. The kit includes 52mm POP UP piston, Caber piston rings (made in Italy, these are an upgrade over the Hyway rings), wrist pin, and circlips. Do you want to add power to your saw without spending money on expensive porting? This POP UP extra compression piston from Hyway will generally add at least 10 psi compression over the stock design piston. More compression equals more power. Caber piston rings are the best you can get and ensure reliable performance. 1 year warranty against defects on this Hyway piston kit. Wolf Creek Saw Shop is a proud U.S. seller, we ship within 1 day of receiving payment, and you will get your parts quickly!