【Compatible】 Compatible with Stihl 064, 066, MS660, MS640, and MS661 series chainsaws. Keep your chainsaw running like new. 【Perfect Compatibility】 Each replacement part is compatible with the original product. High-quality sprocket sets help you easily repair your chainsaw and restore it to peak performance. 【Package Contents】 1 x Clutch Drum, 1 x Clutch Assembly, 1 x Clutch Cover, 1 x Washer, 1 x Chain Sprocket, 1 x E-Clip, 1 x Ball Bearing Needles. 【Easy to Install】 Rim Sprocket: 3/8 inch pitch, standard 7 spline, 7 teeth. Installation and replacement are quick and easy. 【Quality Assurance】 As a professional supplier of chainsaw parts, our products are designed and manufactured according to strict standards.