Shimano Adapter Description:
For 74mm frame or 74mm fork converting from 160mm rotor to 180/203mm rotor.
Model : SM-MA-F180P/P2/SM-MA-F203P/P
Compaliteable Braking System : Hydraulic/Mechanical Disc Brake
Components : Disc Brake PM Adapter
Material : Aluminum
Compatible Models : Mountain Bikes
Size : 180/203mm
Brake Caliper Type : Post Mount
Note : Doesn't come with original packaging, it is produced by Shimano's official factory, buy with confidence.

BUCKLOS Adapter Specifications:
Material: Aluminum alloy
Size: Front&Rear 180/203mm disc.(2 bolts are included)
Components : Disc Brake PM/IS Adapter
Colour：Black,Red,Gold,Blue,Titanium
Length: approx. 102 mm
Bolt Bolt distance: approx. 74mm
Weight:approx. 43.2g

Note: 1. Front Post to Post 180mm = Rear Post to Post 180mm (this is installation in the frame 180mm rotor, and the fork 180mm rotor) 
          2. Front Post to Post 203mm = Rear Post to Post 203mm (this is installation in the frame 203mm rotor, and the fork 203mm rotor) 
          3. Rear IS to Post 180mm = Front IS to Post 203mm (this is installation in the frame 180mm rotor, and the fork 203mm rotor)