The CST 9 is the Vega and Lui expansion chamber developed by Martin Cook. This exhaust is one of only a handful of sports exhausts on the market. These are ideal for any Vega/ Lui, be that be on a standard barrel, an after market barrel or one of Martin Cook's 140cc conversions. Producing, as with all the CST exhaust range, good BHP and torque across a good portion of the RPM range. If your wanting a sports exhaust then look no further! Not only that but they are Hand Made here in Britain!