GFB Whistling Trumpet (only for Stealth FX and WRX Hybrid)

Go Fast Bits WHISTLING TRUMPET (for Stealth FX, Deceptor Pro and Respons TMS over 12 psi)

The 5701 can be used in place of the standard trumpet on GFB valves (Part numbers T9003 & T9503), and will make a whistling sound. However, it is necessary to run the valve so that all (or most) of the air vents through the trumpet ? Respons valves will typically not generate the velocity required to whistle when set to 50/50 venting.