Seller: cameraguy2 (5,916) 100%, Location: Oakland, California, Ships to: Worldwide, Item: 172817117436 Condition: zero issues., Brand: Tiffen, MPN: bay, Details: The threads on the outside measure 30mm. The diameter on the inside of measures 26.5 to27mm as per my calipers....... It's likely I should have posted this as new but the box is gone, the plastic case is not new. The rings might have been used once but no real sign of it. This adapter has zero issues. Be sure you are aware of the size you need before purchasing. If you have a question please ask it.