Features1 Material: Made of aluminum alloy, the 104BCD electric bike chainring and adapter is sturdy and durable, its hardness is higher than those made of crude steel. 2Applicable Models: The 38T chainring conversion kit is suitable for Bafang electric bike mid drive motor BBS01, BBS02, you can use it for corresponding motor. 3CNC Cutting: Adopted of aluminum alloy CNC cutting, the electric bike central drive motor boasts high accuracy, durable and sturdy when in use. 4Lightweight: The 104BCD chainring adapter is light in weight, time and labor saving for you to replace the old or damaged parts. 5Scratch Resistant: The 38T gear adapter chainring can prevent your electric bike central drive motor from scratches, so that to prolong its service life.SpecificationItem Type: 104BCD Electric Bike Chainring and AdapterMaterial: Aluminum AlloyWeight: 170g/6.00ozBCD: Approx. 104mm/4.09inSuitable: For 7,8,9,10,11,12 SpeedsPackage List1 x 104BCD Electric Bike Chainring and Adapter