The AW-3 Dynamic Wah gives your rhythm guitar a choppy, funk sound like many other envelope filters. It features a "Humanizer" effect to emulate the sounds of vowels spoken by the human voice - not all that useful but interesting from time to time. There is also an input for an external expression pedal, though I don't see why you would use one in combination with the AW-3 rather than just buying a nice wah unit itself.

Four controls allow you to adjust decay, mode, and the two vowel sounds for the "Humanizer" effect. It has a dedicated bass input and does reach lower in range than most standard wahs, though it still seems to lack some of the low end thump that bassists might not want to live without.

Keep it towards the front of your signal chain. This rule is flexible with a normal wah pedal, but since this pedal will vary the wah effect based on picking dynamics you may as well not even have it if it's not placed before it hits any dynamics processing.