Mission Engineering Dual Channel Expression Pedal - Aero Style Chassis - Flat BlackThe extended sweep of the Aero design makes this a great all round expression pedal for volume as well as effects parameter controls. The rear cut away and extended length curved surface are ergonomically designed for comfortable use in either standing or sitting positions. The EP 25 PRO has dual 25K outputs with polarity selection, compatible with many devices for guitar, keyboards, acoustic instruments both live and in the studio.