It's a simple brass ring with two different sizes, 67mm and 72mm. The 67mm is the most common size, used on most cameras. The 72mm is a little large, but it will fit some larger cameras such as the Sony A7sII and A9.
breakthrough photography 67mm to 72mm cnc brass step-up ringYes, we support ODM/OEM, we provide custom-made service for clients or even support clients on designing or improving