Have an authentic train horn? How about an authentic train horn valve to control it? This premium train horn valve also allows you to adjust between several different metering options, such as 12 Standard Cubic Feet per Minute (SCFM), 24 SCFM, and 30 SCFM. Trusted by locomotive operators all over the world, the Graham White 353 Series Manual Train Horn Valve delivers unparalleled performance and dependability.