I have a pair of K10UA's. I loved them in the store but since getting them home I have struggled trying to get tips that work well with them. The large Noble red tips worked in the store, I am now back and forth between JVC and Spinfit, and still not completely satisfied. I ordered a pair of custom tips through Null Audio in Singapore, which I am waiting on arriving. I'm hoping that does the trick, but given the trouble I've had I'm not too optimistic.
In the meantime, I tried on the tips I had for my Bose QC20's. They are the Bose StayHear tips. I used to travel a lot and they were the headphones I used on flights. They don't get used so much now, and I forgot about them. Wow, I mean WOW! They are supremely comfortable, and sound really good too. They fit easily on the K10 nozzle. I thought they might be a little loose, but so far no problem at all. Sound signature changes with the different sizes, but for me the Large sound grea, and are really, really comfortable.
If anyone is struggling to get suitable tips for Noble, or for other iem's with 6.5mm nozzles, check out Bose StayHear tips.