This is a popular EP Booster copy. It's said that turning it on increases the gloss and presence of the sound, and for a time, almost every guitarist had one on their board. As you can see from the sticker, this one was made by a well-known person. It's not just a copy; the trim that's usually inside the back cover has been moved to the front, and it has a FAT mode and a bright mode switch that aren't usually included. You can even switch between 9V and 18V operation, which is something you sometimes hear about with the actual EP Booster. It seems to internally boost the 9V input to 18V, so you don't need to use an 18V power supply. Of course, you can also use it as a regular booster by placing it after your distortion pedals. I've lost the original box, so it will be shipped in a suitable box. All the other effects pedals I have for sale are also in excellent condition, so please take a look at those as well.