For the most part this is a good product well built that works nicely and has enough features for what it is. You can connect multiple of these boss switches together with the side rails to create "one board", you can use one cable to control both switches or two cables, one for each switch and you can select latch or momentary.
I use mine on my Boss GT-100 to act as a tuner on/off and a manual mode on/off, with one TRS stereo cable, since the gt only has 1 input for switches.
But... It needs a battery! Which easily knocks the score down by two stars. No it's not just for the LED, it wont work at all without a battery. So every time you're not using it you better unplug the jack, so it doesn't use up the battery.
I dislike the battery part so much, because otherwise it's great and I don't think it needed a battery to do the switching part. At least if there was an option to not use the battery that would be fine, so that in case the battery ran out, you could still use it a little bit.