Control Panel Reverb: One Knob Reverb effect control. It adjusts the Dry/Wet and Decay parameters. Or you can turn it OFF by tweaking to 0. IR Level: Adjusts the simulated signal (Impulse Response file) LEVEL. Select (Push to Save): In manual mode, you can choose the IR file. And you can save your customized preset by pushing the knob. Gain: Adjusts the signal input Gain level. 3-Band EQ: Bass: Adjusts the low frequency level Middle: Adjusts the middle frequency level Treble: Adjusts the high frequency level. IR Footswitch: Manual Mode: Engage/disengage the selected IR file. Acoustic guitar simulation ON/OFF Preset Mode: Bank DOWN. AMP Footswitch: Manual Mode: Activates the pre-amp section. When you engage the AMP, you can use the Gain and the 3-band EQ. Preset Mode: Bank UP. Input/Output Jack Input: 6.35mm (1/4-inch) jack input Output: 6.35mm (1/4-inch) jack output Send/Return: 6.35mm (1/4-inch) effect loop inputs Micro B USB Port: You can connect the pedal to your computer to use the Optima Air software to create, edit and save your presets. And update the pedal when a new firmware released. Power Input: 9V Negative TIP power adapter input 3.5mm (1/8-inch) Auxiliary Input: You can connect music player to play along with music 3.5mm (1/8-inch) Headphones Output: For silent practicing or recording XLR DI Output: For direct connection to mixer (or PA system) Specifications .24-bit, 48-kHz Sampling Quality .Acoustic Guitar Impulse Response and Pre-Amp controls .15 built-in acoustic guitar profiles with IR level control .9 Preset Slots .Reverb Effect .Gain, Bass, Middle and Treble controls .6.35mm (1/4-inch) Send/Return, effects loop / 3.5mm (1/8-inch) Auxiliary input / 3.5mm (1/8-inch) Headphones input .XLR DI Out / Micro B USB Port for USB Audio Stream and Edit Software