this was a steal at this price [SEP] eeeeeeekkk i am so excited about this i love my dry bar buttercup hair dryer but really wanted a diffuser for it because i like to scrunch my hair time to time when i added it to my cart it was i believe that is still cheaper than sephora so i was going to get it but waited so glad i did randomly it dropped to purchased immediatelyit fits my hair dryer perfectly but i can tell by looking at it that my hair dryer is not a standard size on the end so i had to purchase the bio ionic brand since that is who makes my hair dryer worth it it says universal but i would still take measurements to make sure it will fit yours if it is not a bio ionic brand because they are not ever all universalthe part that attaches to your hair dryer is not a hard plastic it is rubbery but firm so it slides onto your hair dryer but does not click into place i think that is why they say it is universal because this allows for some difference in the size of your dryer but still do your research and compare your hair dryer to the size of the buttercup hair dryer because it fits it perfectlyyou can also twist the diffuser to open up the vents or close them to control the air flow see pictures there will always be air flow on the outer ring of the diffuser but you can completely close off the center which is nice if you do not want a ton of forcei love it and it was completely worth it