I've been contemplating this one:
https://smile.amazon.com/Infrared-Professional-Negative-Diffuser-Concentrator/dp/B07RM3KKXV/ref=sr\_1\_6?crid=3VN6NRSL3KXNI&keywords=infrared%2Bhair%2Bdryer&qid=1641618295&refinements=p\_n\_feature\_browse-bin%3A10737475011&rnid=370232011&s=beauty&sprefix=infared%2Bha%2Cbeauty%2C86&sr=1-6&th=1