Diaz Tremodillo Tremolo pedal. These are a boutique and now discontinued trem handmade by renowned guitar and amp technician Cear Diaz. It's a solid state circuit that works like an old Fender tube amp: when it's engaged, it cuts the signal. It's certainly gathered a some fans; there's plenty of high praise around the internet to be found and high profile users include R.E.M. and Pearl Jam. Vintage tube amp trem in a box, fun!
Model: Cesar Diaz Texas Tremodillo
Power: regular 9v supply or battery (not included)
Accessories: none, no box or manual
Condition notes: some minor scratches, mostly on the bottom. Overall: very good condition
Here's a reasonable demo to give you the idea.