Shimano BR-RS305 Disc Brake Caliper (set)

Set includes front & rear calipers
Flat mount mechanical road disc brakes
Compatible with all current Shimano Super SLR brake levers and STI
Wide and adjustable pad clearance
Light weight, low profile one-piece forged alloy body
Long arm design maximises performance
Includes L02A Ice Tech resin pads with fins
Shim-less mounting, easy to set up
Weight: 170g per caliper
 
One Shimano disc brake mount adapter (SM-MA-R160D/D) is required if installing a 160mm rotor on the rear. The front brake caliper (somehow) already comes with a 140mm/160mm mount. Note: this is true regardless of the frameset you are using.
Two Shimano 10mm flat mount caliper fixing bolts are required for installation of the rear caliper on Beagle 13 frames. This applies whether using 140mm or 160mm rotors. In the case of 140mm rotors: the 10mm fixing bolts mount the caliper directly to the frame. In the case of 160mm rotors: the caliper is first mounted to the adapter (see above) before using the 10mm fixing bolts to mount the adapter to the frame. Note: the bolt spec (10mm) refers to the internal thickness of the chainstay (not the actual bolt length) and the bolt required will or may vary from frame to frame.