This is an innovative 'one spot' adapter, basically an adapter that only takes up one spot. You can purchase daisy chains to power up to 8 pedals for each adapter. It's worldwide usage is what makes it quite popular in my opinion and the fact that it actually works is also helpful!

There have been many debates about using power adapters over brick power supplies etc and yes I used to use a brick power supply, a few different types of which have been very great! However the 1 spot seems to do the job just as well I think. Of course there are disadvantages and advantages to using either but it also depends on the budget and what type of rig you've got etc. I think most everyday jammers and casual giggers would probably suffice with this type of power supply. It's relatively low noise and reliable. While most pro gig players would probably have that peace of mind with the power supplies.

Oddly enough I went from using a huge board and a power supply down to just less than 5 pedals and the 1 spot and I haven't had any troubles in live situations. I've also seen a few of my guitar player buddies in their bands using the 1 spot with their boards and live, I didn't notice any extra noise or see them struggle with powering anything. They're the ones that convinced me to simplify my rig to a most 'realistic' rig. The fact that it provides more MA than anybody usually needs means that you power nearly anything with it! Great, good, quick!