Cavision's Universal Lens Donut Adapter Ring snaps into select matte boxes with a 100mm rear opening and serves as an anti-reflection donut for lenses with an outer diameter between 60 to 95mm. It utilizes a flexible fabric that allows for lens travel so it is suitable for use with lenses that exhibit up to two inches of lens travel when focusing or zooming. The flexible fabric features a draw string and cord lock.
Suitable for DSLR or other external focus lenses as well as internal focus lenses without lens travel.
The flexible fabric provides an adjustable opening that you tighten to the lens to prevent light from behind the matte box flaring filters and degrading your image.