Mojo Gear Fx Red Boost is based on the original rangemaster circuit, but introduces more tonal options. It's build with high quality components and unique design. This one uses NOS germanium transistor . You can choose between AC125 (stock) SFT308 (closest sound to OC44 for the money) and even OC44( like the original Rangemaster). The pedal accepts 9V DC center negative power supply and battery. And like all of our guitar pedals it's true bypass.