Optex 62mm Variable ND Filter lens mount_C Mount 6 II USM is a

6 II USM is a compact standard zoom lens for film or digital EF-mount cameras

If you're building a darkroom

and an 8GB Sandisk Extreme III CF card

Optics show some cleaning marks

Optex 62mm Variable ND Filter lens mount_C Mount 6 II USM is aThe Optex Variable ND is a good quality filter that lets you dial in between 1 and 8 stops of neutral density ideal for changing lighting conditions. For lenses with a 62mm filter thread. While the filter will screw onto 62mm filter threads, the front of the filter uses a 72mm thread. The filter uses hard stops on either end of the rotation, so you can feel when you reach each extreme. In excellent condition.