Replaces Stihl 017 018 021 023 025 MS170 MS180 MS210 MS230 Chainsaw Replaces OEM Number: 1123 640 1705. Package Contents: 1 Sprocket Cover , 1 chain adjuster, 2 nuts, 2 studs. High quality spare parts. Please compare your original products carefully with the photos if you are unsure. We offer other matching items and accessories.