The SmallRig 3409 Silicone Donut is designed for use with matte box systems to help prevent light leaks during video production. Its flexible silicone construction adapts to different lens diameters while maintaining a secure fit inside compatible matte boxes.

Featuring a 114mm rear opening, lightweight build, and foldable silicone design, this accessory supports efficient lens transitions in professional filmmaking setups. It is suitable for cinema camera operators, videographers, and content creators using matte box configurations in studio or outdoor shooting environments.