The Phidgets #25 Chain Sprocket w/ 11mm Bore & 32 Teeth is crafted from hardened steel, designed for compatibility with a quarter-inch roller chain. It features an 11mm bore equipped with a keyway, ensuring a secure fit onto an 11mm shaft. The sprocket is engineered to provide a robust connection through a 4mm keyway and is secured with two 2mm hex screws, making it suitable for use with #25 size chains.