From pswpower
Chainring spider/adapter for bafang BBS01B and BBS02B. It is suitable for 32T-48T chainring with BCD being 104mm or 130mm. If the original Bafang chainwheel does not meet your requirement, you can consider buy an extra chain ring and chainring adapter.
Packing list:
1). One chainring adapter
2). 4pcs or 5pcs black stainless steel bolts
Note: The chain ring is not included.