The Optum Ring System (ORS) is a removable ring that can be mounted in eight different orientations within the 29mm Optum scope body. Features an adjustable fiber cover to control ambient lighting. Available with a .010”, .015”, .019”, .029”, and .039” pin option as well as a no pin option (all pins are removable). Threaded on the target side to accept a lens housing or sunshade. Integrated 8-32 light port allows the use of an electronic light kit to illuminate the fiber and pin. Fiber bypass slots let the user wrap fiber around the ring system to collect additional natural light. Made in the USA