32DP gear material is 45 steel (also known as 0.8M in China), the inner hole is all positive tolerance 0-正0.03, M4 fixed screw hole Easy installation and long service life Hard anodized gear surface Anti-rust treatment on the surface of the gear Suitable for 1 / 8 RC model car 5mm shaft brushless brush motor 19T 5*16.67*14mm