If all the existing adapters supplied with the camera cannot meet the yours need, (such as the situation where the BFL requirement is very special), QHY offer this all-in-one accessory package. This includes almost all kinds of M54 adapters available. You can get any BFL you want through this kit.
The kit includes
5mm M54 to M48 Adapter*1
3mm M54 to M42 Adapter*1
2.5mm 2inch Filter Fixer (Original Name 020055) *1