This original bumper strip (bumper strip) is a key safety and protective element mounted on the sprocket cover (chain cover) or on the engine housing itself. Its primary technical function is twofold: it prevents direct friction and wear of the aluminium or magnesium cover caused by the movement of the chain and the seating of the guide bar, and at the same time protects the structure of the saw from damage in case the chain breaks or comes off at high revs. Fitting this original steel strip ensures correct sliding and reduces the transmission of vibrations to the housing, thereby extending the service life of the sprocket cover and preserving the geometry of the cutting tool. When replacing the bumper strip, it is extremely important to thoroughly clean the inside of the cover of the crusted mixture of oil, sawdust and resin so that the new part sits perfectly in its intended seat. Check the condition of the locating pins or screws that hold the strip in place. During installation, the strip must be perfectly aligned with the edges of the housing and without any folds that could catch the chain. Tighten all fixing elements carefully, following the factory channels, and after installation turn the chain by hand (with the engine off and the chain brake engaged for checking) to make sure there is no unwanted scraping or resistance anywhere. Key features Part type: Original part (OEM) Catalogue number (OEM): 1121 648 6610 (11216486610) Installation position: Sprocket cover / Housing (Chain sprocket cover / Crankcase) Function: Protection of the housing and cover from impact and wear, and cushioning of contact with the chain Material: High-quality spring steel resistant to friction and high temperatures Unit of measure: Sold per piece Compatible models STIHL chainsaws (professional, farmer and hobby class) STIHL MS 240, MS 260, MS 271, MS 290, MS 291, MS 310, MS 311, MS 390 STIHL MS 341, MS 361, MS 362, MS 362 C-M, MS 363.0, MS 381, MS 382, MS 400.1 C-M STIHL MS 440, MS 441, MS 460, MS 461, MS 462, MS 462 C-M, MS 500i, MS 650, MS 651, MS 660, MS 661 STIHL MS 880, MS 881, MSA 300.0 STIHL 024, 026, 028, 029, 034, 036, 038, 039, 044, 046, 064, 066, 084 STIHL electric saws and hedge trimmers STIHL MSE 220, MSE 220 C, E 14, E 20, E 20 C STIHL HS 242, HS 246, GS 461