The Mooer Micro ABY MK2 can be used as an A/B or Y switch. The signal can flow from A or B to Y, or the signal can flow from Y to A or B. The pedal can work without power supply but the LED will not light.
"This product is as straight forward as it get. You want to switch between two channels? The Mooer ABY MK2 got you covered. I especially love the small foot print cause my pedal board is pretty tight. There was no leek of sound between the 2 channels. That means that when you were in channel A then there will be absolutely no signal in channel B (not to my ears atleast). Although this pedal has an extra channel, channel y, which takes your signal and simultaneously play if on both channel A and B hence the name ABY. I personally don't have a use for that particular function nor do I see it being useful for anything really, but it is there and it might be useful for people more creative than myself."