Here's the 2nd incarnation of my optical tremolo pedal, this time with an extra footswitch to select between two different rate controls. The top LED pulses in time with the oscillator so the two different speeds can be dialed in even when the pedal is in bypass mode.
I am terrible at photography so you'll just have to take my word that the enclosure from Kirk at Pedal Parts Plus is truly gorgeous. It appears green from one angle, purple from another.