Singh Ray Daryl Benson ND-2 Rev. Grad. for Cokin PThe Singh Ray Daryl Benson ND 2 Rev. Grad. is a 2 stop "reverse" graduated neutral density filter designed to fit in Cokin P filter holders (sold separately). A reverse graduated ND filter is darkest in the centre, like a regular grad ND filter. But unlike a regular grad ND filter, which gets darker closer to the edge, a reverse ND lightens up: you can see this on the image. A high quality filter in excellent condition.