The e*spec 104BCD Carrier Spider facilitates the use of any 4-bolt standard 104BCD chainring on e-bikes for less expensive chainring replacements and reduced waste. Forged from 6-series alloy for light weight and stiffness it can be paired with long-wearing steel or lightweight alloy chainrings. Chainring BCD 104 Color Black Defined Color List Black Designed for ebike Yes Interface Standard Shimano EP8