MXR® SMART GATE® PRO RACK UNIT M235 This brilliant rack piece features the same great noise reduction as the pedal, but with the added features of two discrete channels, a Sync function, selectable ground lift, and remote switching capabilities. This brilliant rack piece is the big brother to the Smart Gate pedal. The Smart Gate Pro Rack Module features the same great noise reduction as the pedal, with three selectable ranges (Hiss, Mid, and Full) and a precise threshold trigger. But the Pro features several upgrades and enhancements. For starters, the Pro has two discrete channels, making it possible to set one channel to Hiss and minimal Threshold level (for clean tones) and one to Full and a higher Threshold level (for high-gain lead tones). There is also a Sync function that links the two channels for quieting a stereo signal. Add to this the true hardwire-bypass on each channel, selectable ground lift, and remote switching capabilities (with status-indicating LEDs) and the Smart Gate Pro starts to look like a real genius.