Close he Shimano BL-MT401 lever with the BR-MT401 calliper is the perfect braking upgrade for your MUni or Road Unicycle. This is a great quality hydraulic brake system at a great price.  The kit comes with everything you need to convert a disc ready unicycle in to disc unicycle (except for the brake lever mount for saddle).

Comes with Lever, Calliper, Hose, IS Front Mount, 180mm Rotor and all necessary hardware.

Dual piston BR-MT401 forged aluminium post mount callipers.
1200mm plastic hydrolic hose.
Integrated bleed port that uses mineral oil - this is non-corrosive and less hazardous than other oils (this brake comes fully bled and ready to install).
Post mount to IS adaptor ready for 180mm disc.
180mm Disc Rotor.
2-finger BL-MT401 levers with aluminium master cylinder, tooled reach adjust & anodized aluminium lever.
Weight: 300g (Lever, Hose, Caliper & IS Mount).

Here is the Bike Mag Review of this brake - Shimano Improves Entry-Level Components