77-77mm / 80mm OD Cinema Adapters (20mm wide)Complete your cine conversion with a cine spec adapter ring with 77mm front threads Rings are 20mm wide for tighter focal lengths (35mm and up) 80mm outside diameter that fits perfectly with 80mm clamp on lens adapters for your matte box to defend against unwanted lens glare and stray light Stabilizes the lens when used with 80mm matte box adapters by adding a second support point. Torque from follow focus units will not move the lens, which can be a