Review (4/5): IF your blowdryer is a match for this diffuser, you are going to want it for lift and volume. Nothing else compares.
Several years ago I had purchased a blowdryer with a similar attachment. I absolutely adored that thing - you could use it on the top of your hair or the sides to give lift so your hair had volume without using any product or doing any backbrushing. The thing was a miracle worker!
Then we entered the era of pin straight hair, and volume and body were out. Thank God, we seem to be passing that era, but hairstyling implements seem to be lagging behind. I was dying to try this diffuser to see if it emulated the gizmo from long ago, and it does. Well made hair styling tool that gives lift and volume to your hair, I love it. Well, kinda.
I'm not sure how 'universal' this is. I tried it on my current blowdryer, and it didn't fit. I had to go digging around until I finally found a Conair dryer upon which it fit, and the funny thing is that it fit like it was MADE for the dryer. The odd thing is that the Conair looks to have the same kind of nozzle the other blowdryer had, so go figger.
IF you have a blowdryer that marries this diffuser well, this is definitely something you're going to want in your hair arsenal. It'd almost be worth getting a new dryer just to use this, it's that good (one star off for the weirdess of the 'universal' claim.)