not universal [SEP] i have a pretty basic blow dryer it is a standard size i cannot for the life of me get this on my dryer also i know a lot of people buy this specifically for the dyson and the black orchid diffuser i ended up returning my dyson but still wanted to use this on the black orchid and my regular dryer the diffuser does not have enough surface space for this to really get a good grip and stay on and it is a pain in the butt to put it on over and over i do not know how you all are doing iti am keeping it because i do not have a printer to print a return label but i would really like to return it since i am not able to use it