As pictured.

Description
Brake bias valve with a reducing range from 0-60%. 
Allows front to rear brake bias adjustment for single master cylinder applications.
This is used and supplied to Professional Race Drivers, Race Teams and most Race Car series world wide including Pro-Drift, BDC, BTCC, 750 MC etc. 
Inlet and outlet ports are 1/8NPT.

Application
150PSI - 1200PSI pressure range Suitable for motorsport use
Enhances control under braking
Greatly aids turning under braking