The Kirk NC-300 Replacement Lens Collar is specifically designed for the Nikon 300 mm f/4 AF-S lens. It is designed to provide maximum lens support, with quick, accurate, smooth rotation and positive locking in any position.
Precisely machined from lightweight 6061-T6 aluminum, the base is made to fit a Kirk Arca-Swiss-type quick release clamp. In addition, instead of only one point of support, the NC-300 provides an additional point of support for the lens at the other end of its plate.
Reviewed by 2 customers
It's solid, smooth and works well. Nikon should have included a collar that was this good.
The mount is very well made and even when I hand hold the lens, it provides a solid resting place in my palm. It's easier to remove than the Nikon version. I purchsed this used from Adorama and frankly couldn't find any evidence of use. I like the fact that it incorporates the Arca-Swiss dovetail, although it can also use the standard 1/4 20 tripod tread.