Z.VEX Effects Tremolo Probe, from Zvex

The Tremolo Probe is a kind of cross between a theremin volume control and a Super Hard-On. There is a 3-5/8" square copper plate mounted on a chunk of 3/8" clear acrylic that passes over the top of the pedal housing, angles down to sharp turn, and goes back to the pedal. Under the whole mess is a 3 5/8" by 7" sheet of aluminum that provides shielding from annoying ground effects and wires under the stage. It also serves to protect the knob from being knocked off if you drop it on that end... and it makes a nice toe chopper if you are barefoot, so (legal disclaimer:) DO NOT DROP THIS PEDAL ON YOUR FOOT! IT IS HEAVY AND HAS VERY POINTY CORNERS THAT COULD DAMAGE LIVING CREATURES AND FINE HARDWOOD FLOORING. ALSO, YOU COULD BREAK SOMETHING. Like your dog.