One of the loudest valves in the GFB range can now also be one of the quietest - choose between silent and stealthy operation, or an ear splitting WHOOSH!The Mach 1 and Plumback valves have now been combined into one affordable unit - the new Mach 1 kit comes complete with the parts required to make this valve vent to atmosphere for maximum noise, or plumb back for silent - and very importantly - LEGAL - operation.Like the Stealth FX and Deceptor Pro, the Mach 1 is now also available in a black anodised finish for those who prefer keep things a little more clandestine.The Mach 1 comes standard with a 35mm base (part # 5035), which can be hose-mounted into 32-35mm I.D. hose, or pipe mounted onto 1" metal pipe. A short length of 1" steel pipe is included in the kit for custom weld-on applications. The supplied plumb back outlet is 30mm (part # 5230).A range of different sized hose adaptors and model-specific bolt-on adaptors are available if required, click this link for more info.Colours available: red, blue, silver or black.