First establish the Type of mount for your Caliper, Fork or Frame.
Type 1: IS (International Standard) - holes at 52mm centres.
Type 2: PM (Post Mount) - holes at 74mm centres.
Notes: All part codes start with OBE example BMS120 has full part code OBE-BMS120
Almost all Frames have IS mounts.
Our descriptions quote the Caliper first and the Fork or Frame second
example PM to IS means this adaptor is for Post Mount Caliper to be fitted to an IS Fork of Frame
For IS Caliper To IS Fork or Frame - see BMS118, BMS120 or Kits BOS18, BOS20.
For PM Caliper To IS Fork or Frame - see BMS318, BMS 318-1, BMS320 BMS 320-1, BMS32R. BMS618G, BMS620G
For PM Caliper To IS Fork and 20mm IS axle - see BMS418, BMS420
For PM Caliper To PM Fork (including Manitou forks) - see BMP518, BMP520
For IS Caliper to PM Fork - see BMP120 (This item is for a 203mm rotor only. You can see more details at www.discobrakes.com)