New and high quality.Fine workmanship and perfect style.Easy to install and durable in use.Strict quality control standards to build and test.High Wear-resistant and excellent durability.Suitable for replacement of central HD 1000W central motor cranksetNumber of teeth: 42 teeth (positive tooth thickness 3.6mmx21/negative tooth thickness 1.9mmx21)Maximum diameter: 175mmMaximum height: 24.3mmTooth pitch: 12.7mmThreaded hole diameter: 5.2mmInner hole diameter: 41.2mmSurface treatment: sandblasting + Surface roughness: about 120 meshWeight: 212gMaterial:7075 aluminum alloycolour:BlackPackage contents:1 x motor cranksetOnly 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.