An A/B toggle switch with 3 reverb effects. When on A setting, has a bit more gain, but doesn't effect tone. Very clean on B setting, and still doesn't effect tone. Not bad for the price, not the most colorful reverb. Input, output, and power jacks all came apart with use and travel.
I was a little skeptical because Biyang seems like a "cheap" pedal company but similar to Joyo they are surprisingly good. The different room sizes give you a lot of options and I can match pretty much any reverb just with this one pedal. Love it!