This is a mouthpiece I've used for about six months. Inner cup diameter is 27mm, rim thickness is 6mm, and rim width is 5mm. There are a few scratches on the part inserted into the instrument, but otherwise, there are no scratches. I want to sell it, so please let me know if you'd like to negotiate the price. *Please refrain from purchasing if you are concerned about hygiene, as this is a used item.