Two classic distortion/overdrive circuits combined into one pedal. Swap tone controls and/or distortion sections to create new sounds. By mixing the SD Overdrive and RT Distortion, you can create two unique Hybrid Distortions.. Silent Buffered Bypass or True Bypass – hold footswitch for one second to change. Professionally Engineered and Expertly Manufactured Pro Audio Gear – sounds developed in the Keeley tone lab and in the field, then built entirely in our factory.