I have two of these in great condition. Always racked, very clean. http://www.sweetwater.com/store/detail/FeedbackFerr I have used these with my wedges for the last couple of years. Great when/if you don't have time to fine-tune your wedges, or if you just don't want to carry a rack full of 31-band EQs. Peavey says that the filters set by these devices are far narrower than a 31-band. These devices work seamlessly with no sonic footprint that I can detect. Everything sounds normal, but there's no feedback. Each device can handle two sends in "stereo" mode, or you can use them in mono mode if you want all of the filters available for one send. The devices will remember the filters even after you cycle the power. Fantastic for that small practice space where you're cranking a little PA to get over a loud drummer. Even better for a fixed installation like a church. If you have someone who wanders all over the place with a lapel mic, you'll be able to get much better gain before feedback. I need $90 shipped and PP'd. No trades please.