The Husqvarna 537219602 Pop Up 46mm Piston Assembly supports proper engine compression and piston movement for reliable equipment operation. This replacement assembly fits within the engine cylinder and moves up and down as part of the combustion cycle, helping convert combustion force into mechanical motion. Proper piston movement supports efficient engine performance and consistent ... https://www.wholetoolbox.com/husqvarna-537219602-pop-up-46mm-piston-assembly/537219602.html