New and high quality. Fine workmanship and perfect style. Easy to install and durable in use. quality control standards to and test. High Wear-resistant and excellent durability. Suitable for replacement of central HD 1000W central motor crankset Number of teeth: 42 teeth (positive tooth thickness 3.6mmx21/negative tooth thickness 1.9mmx21) Maximum diameter: 175mm Maximum height: 24.3mm Tooth pitch: 12.7mm Threaded hole diameter: 5.2mm Inner hole diameter: 41.2mm Surface treatment: sandblasting + Surface roughness: about 120 mesh Weight: 212g Material:7075 aluminum alloy colour:Black Package contents: 1 x motor crankset Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.