This Pedal is currently available.
True Bypass Looper w/ Feedback Loop
Switch multiple pedals on and off at the same time, without the toggle activated it functions as a normal true bypass loop pedal, allowing you to isolate and bypass pedals that are not true bypass, switch on/off groups of pedals (or all your pedals) at once.
The feedback function of the looper is designed to send the output signal back to the loop's input through a potentiometer. This can produce some some very interesting results ranging from oscillating, growling, chirping sounds, to flat out noise, to nothing.
Some pedals can produce great results while some have little to no effect at all. You can also try various combinations of pedals. Your pickups and pickup selector position as well as your volume and tone controls also have a tremendous effect on the sound produced. The pedal's control knob determines the amount of feedback being sent back to the input. Sometimes you may need to turn it all the way up while other times you may find a sweet spot with the level turned low. If making a lot of complex noise is something you're into, then look no further.
This pedal is passive and doesn't need power to work. The power is only to make the LED light up. The LED runs on standard 9vDC center-negative power. Hand made in Hong Kong.
https://acpeffect.com/products/A-C-P-Hui-True-Bypass-Looper-w-Feedback-Loop-p405999709