The Hotone Soul Press is a 3-in-1 pedal in a smart compact size. The unit features Wah, Volume, and Expression modes.

WAH: Wah mode is for all the cry babies out there—we're talking about the legit vocal sweep and lush harmonics of the wah's classic era.
VOL: If musicians the world over agree on one thing, it is their common hatred of the "tone sucking" quality of passive volume pedals. Soul Press’ Volume mode is an active volume design, which keeps your tone ristine. Fine tune the bottom end with the volume range control.
EXP: Expression pedal mode can be used without a battery or external power supply. It is compatible with most digitaleffects and connects with a standard stereo 1/4" jack. This mode also supports keyboards and other instrument that use expression control.