HIFROM TM Replace Oil Pump Worm Gear Replacement for Stihl 017, 018, MS170, MS180 New Replace # 1123 640 7102 1. New high quality aftermaket replacement Worm Gear 2. Fit for chainsaw models 017, 018, MS170, MS180. 3. Replace part # 1123 640 7102 4. This is non original aftermarket parts, please check the pictures for compatibility before buy it . 5. HIFROM focus on provide high quality products at fair price, if you unsatisfy with our product, you can return to our USA warehouse, no risk.