These units control single reverb, tremelo, delay, etc.. in amps and devices that have 1/4" mono jacks installed for turning them on or off. (One unit turns the effect "on" and "off") Just plug a c
ABle in the "Channel/Effects
Switcher", and run it to your amp or whatever device you want to turn on and off.
These units work great and are built to last using Die-Cast Aluminum enclosures, 3PDT switches, and (1) Switchcraft jack.
DIMENSIONS: 1.9" X 1.9" X 1.0"