This 12 speed E-bike chainring is designed to work with the Shimano STEPs drive system. It features Shimano's Dynamic Chain Engagement+ technology, which delivers smoother pedalling performance and superior chain retention over bumpy terrain conditions. Technologies: Dynamic Chain Engagement+: SHIMANO’s DYNAMIC CHAIN ENGAGEMENT+ is a special gear teeth profile designed for use in single-chainring configurations for XC, enduro, and trail riding. It gives more chain retention and smoother pedaling - even over bumpy terrain. Chain retention of any gear will reduce abrasion and worn out.