TC Electronic Crescendo Auto Swell Guitar Effects Pedal

From the listing

Seller's description

Every once in a while an effect arrives ahead of its own time, and before guitarists can figure out what do with it, it’s no longer available. As a result, and in spite of their high retail price, they become extremely valuable because of their rarity. Crescendo Auto Swell brings one of those iconic and rare effects back to life, and makes it readily available, affordable and built to withstand a lifetime of abuse. Now you van get those sweeping swells from your guitar, without searching high and low for hard-to-find vintage gear. Thanks to just 2 knobs (Sensitivity & Attack) and a true bypass switch, Crescendo Auto Swell is easy to use and functions much like a noise gate, only in reverse. Instead of clamping down on the tail of your signal, the pedal mutes the initial attack and then swells up to full volume.