MXR M135 Smart Gate Noise Reduction Effects Pedal Tame your hissing high-gain amp or silence your string of effects pedals with this ingenious pedal. The MXR M135 Smart Gate suppresses annoying background HIS, SIZZLE, and HUM noise on your guitar's pure signal. It's a great effects pedal for engaging when needed to clean up background noise, but lets your guitar signal get through. This includes single coil hum and any excess noise you don't want interfering with your clean signal. The Smart Gate is most effective when placed at the end of your signal chain, heading into your amp or sound system. That way, it catches and suppresses all the trash and lets your good signal go through. It features: Trigger Level Contro Gate LED High Trigger Range Control 3 Band Noise Cut Switch True Bypass Foot Switch and blue LED Power: 9 volt battery or 9 volt AC adapter, such as the ECB-03 As MXR says "it lets you significantly eliminate signal noise, while maintaining playing dynamics."