From the MXR Custom Shop, the Variphase is a killer twist on the classic Phase 90. Variable speed control is operated by your foot, adding a shimmery velocity to lead passages or a more dramatic swoosh to muted strumming. Vary the speed from a subtle, long cycle to a fast, watery warble, and everything in between! On/off switch, volume, and mix controls. Uses 9V battery or optional Dunlop ECB-003 power supply.