Prescription Electronics Throb Tremolo pedal in great working order. This example has been heavily toured & on & off a few boards. Serious (super??) glue residue on the bottom after the heavy duty velcro strips were pealed off. Switchable between 2 speeds that share a common intensity control . Chop/Trem settings via mini switch.
Many small marks, chips & signs of player wear.

The circuit seems original, this one has a battery clip fitted, though only tested through the 9V power jack.

From effectsdatabase;
Based on the Electro-Harmonix Pulsar, this tremolo has two speed and one intensity knob for superior wobble control. Super quiet, and known as a  pedal "designed for sick and twisted musicians" by  Guitar World Magazine