Great bit of gear. Everything you'd want in an AB switch. Two outputs and two inputs. Can use it to switch one guitar (or other instrument) between two amps or drive two amps from one guitar. Two level controls allows level tuning. Also great to use where you want to split your guitar/instrument signal to record it dry and also send out to a mic'd cab.
It has a seriously robust housing and the footswitch buttons are tough. No
Got this one off Amazon where they are often available at a significant discount; Morley also make a cheaper version that is just an AB switch (without the mixer/combiner functionality). Morley also make a version of the ABY that functions like a splitter.
One thing I really like about the Morley gear is that they make the schematics readily available. The pedal has been reliable, but its nice to know that if I fried something inside it, I've got the schematic to help me repair it. Look here for the ABY Mix schematic in pdf format.