(I got the wrong one. I got the classic style when I ordered this one. )
Edit: I was sent a new one that was correct. This product really works, it essentially makes any mouthpiece a megatone, some even argue that these sound better on standard mouthpieces than a megatone does. Highly recommend.

I understand what this does, I don't get why - but it does work. And I don't get tired as quickly. UPDATING: I've been using it for about 6 weeks now. It allows me to play softly and maintain good tone and pitch easily, with or without a mute. I also seem to be able to play consistently higher, with less effort, and longer. It makes practicing fun, too, since I can play better, longer - and in turn, that makes rehearsals and concerts more fun. If you're hunting for a unique gift for a young trumpet player (or even an IHOP discount qualifying early bird dinner bifocal balding fossil like me), this would be a good one. I don't think I've had this much fun since I tied some roman candles to a couple dozen helium balloons and sent them drifting over the local "naturist" camp picnic one evening. (Officially, it's not funny and my probation officer would not approve of this post. Had there been cell phone videos back then, it would have gone viral, and that evidence would probably have resulted in a "period of confinement". But if I'd had a mouthpiece booster, I'd probably have been playing my trumpet and not been engaged in atmospheric pyrotechnic misadventures and not inadvertently creating spontaneous excretory problems for the clothing optional members of society.) So, keep your horn players off the streets and keep society safe. Get 'em a mouthpiece booster.

creates a noticable tone to the instrument

Since the first try of the KGU mouthpiece booster, I've notice the difference in my trumpet's sound. It has become so better, I concretely mean warm, expanded, open and brighter. On the high register, now it sounds clearer and with more steadiness. Besides, the appearance of my horn is a bit more pro. It fits perfectly in my Vincent Bach mouthpiece, and it will fit in most mouthpieces, since it has an adaptable mechanism. In general, I now play with better quality sound and enjoy more mi practice time as well as my performance. I recommend it.

Man! I love this mouthpiece sleeve. It adds the perfect amount of weight to a standard weight mouthpiece. I am using mine with a Bach 5B and it certainly improves the slotting and tone. It also looks fantastic on the horn. Expertly crafted, the guys at KGU are amazing. This is an excellent mouthpiece sleeve for a very good price! Get it!