The Boss PCS-20 A is an eight part daisy designed for use with Boss pedals. I've had mine for about five years and have it hooked up to a Boss TU-2 tuner that powers the best of my Boss pedals. I love having this in my set up because it allows me to power all of my Boss pedals with a single AC power adapter that I plug into the TU-2. The Boss TU-2 is one of a few pedals that will power the rest of your pedals. The Boss LS-2 Line Selector pedal will do the same, in addition to a few other models. I believe that this will also power any other type of non-Boss pedal if it also requires nine volt power. However, unless you have one of the Boss pedals to power the rest of them you cannot really use the Boss PCS-20 A. This being said I would only really recommend those using a few Boss pedals to invest in the Boss PCS-20 A, because even though it is convenient, I do not now how compatible it is with other types of pedals. The price of the Boss PCS-20 A isn't that expensive, but is probably a bit more expensive than you would think. It is definitley worth the price if you use a bunch of Boss pedals as it makes your life a lot easier when it comes to setting up your pedals and will also save you a ton of nine volt batteries. I've definitely come to trust Boss when it comes to their pedals and their pedal accessories because they are generally well built and will last a while. All in all, the Boss PCS-20 A is a must have for those of us who use a few different types of Boss pedals at once.