I'm going to buy an iphone 8 soon and I know it dose not have a 3.5" headphone port, so what Bluetooth adapters/headphones do you recommend, my current headphones sennheiser hd201
You've not mentioned a price range so I'm going to suggest the expensive but excellent B&O H7s. We have 2 pairs of these and both looked new out of the box and work perfectly. A big advantage is that they have easily sourced removable batteries so even though they have a 20 hour life it's easy to extend that. I have Bluetooth dongles that work well but I think you may find that together with the headphone cables they make them too bulky and awkward to use. You may find the batteries on these are a bit variable as to capacity but the seller will send you another one without hassle if you complain. For a pair of cheap Bluetooth earphones these Esonstyle are pretty hard to beat at that price and are surprisingly good provided you get a good 'seat' in your ear canal.
If you like your HD201 and don't mind staying wired you might be better off with a lightning adaptor.