A mini version of the switchless, optical skeleton wah measuring 6.75 inch. long x 4.5 inch. wide x 2.75 inch. high. Set to DJ's preferred wah sweep and tone. Optical wah means no pots to get scratchy and wear out! Equipped with internal wah level trimpot, TrueTone Bypass buffer circuit, cold-rolled steel housing, LED indication, quick clip battery door and one-year warranty. Powers from 9V battery or Morley 9V adapter. Also, the entire pedal glows in the dark! Works with guitar, bass or keys!