Hallman's Pro RX kit is essentially the Pro kit with a ceramic ball instead of a steel ball. This allows for very specific boost control, and very fine adjustment for those only raising their boost a few pounds above stock. Boost can be adjusted consistently in 1/2lb increments with the Pro Rx. For those looking to add more than 5psi, the Pro RX also includes a stiffer spring.
Includes: Soft & stiff springs, 3 ft. vacuum line, mounting bracket, mounting clamp, hardware packet and instructions.