Review title is It expands when it gets hot [SEP] So, I bought this to use my black orchid diffuser with my hair dryer. And it does that, it extends the opening and they fit snuggly together before using the hair dryer. About 5 minutes in, the rubber has gotten soft and expands and the Black Orchid slips right out. I tried it with a generic diffuser as well and it behaved the same way. So, if you don't mind burning your hands on the hot diffuser to stick it back on, this is the one for you! 😑