CARB CARBURETOR KIT FOR STIHL 041, 041 FARM BOSS 045 051 056 076 TILLOTSON RK-21HS Superior Quality Aftermarket Carburetor Rebuild Kit Made to meet or exceed OEM specifications. Complete kit, includes welch plug, screen, needle & inlet lever. OK for use with fuel containing up to 25% Ethanol Replaces TILLOTSON RK-21HS