This cost me an unbelievable £12 new! It needed a mod which is explained on eBay before its switch would work well, but having done the work it's now impossible to accidentally switch it off, unlike many far more expensive pedals. As for the sound, it goes Wah! Sorted.
The only bad thing that the Wah haves is that it needs some mods after buying. First: place again the Wah pot for get an ideal range frecuency, Second: Cut part (Like 1/8in. Only) of the piece that press the button on.and off for more range, Third: You need to make it "True Bypass".
But after the mods this pedal works like heaven.