Feature:1. REPLACEMENT FOR STIHL CHAINSAWS: Clutch kit set is suitable for Stihl chainsaws 017 018 021 023 025 MS170 MS180 MS210 MS230 MS2502. SPUR SPROCKET WITH 3/8 LP PITCH: 3/8 LP pitch spur sprocket replacement part numbers are 1123 640 2003, 1123 640 2073, very versatile3. 1123 640 7102 WORM GEAR: The worm gear replacement part number is 1123 640 7102, fit can be used, meet your using needs4. 1123 160 2001 REPLACEMENT PART NUMBER: The clutch pack replacement part number is 1123 160 2001, equipped with bearing, washer and E clip, easy to install5. EXCELLENT ALLOY STEEL: Made of good quality alloy steel material, possess smooth surface and greatly improve the service lifeSpecification:Item Type: Clutch KitMaterial: Alloy steel.Package List:1 x Sprocket 1 x Clutch1 x Sprocket Bearing1 x E Clip 1 x Washer1 x Clutch Cover