This was the first time I've ever really used a spring reverb unit in an instrument. It's got three oscillators feeding through it with a variable voltage control. One 1/4" mono output, on/off toggle and it runs on a 9v power supply. Also, you can toggle the oscillator signal to the output on and off, so you can hear either just the creepy moans and wails or the wails with beeps and screeches. It's lightweight and pretty durable. I'm gonna build more of these!