The Kirk NC-300 Replacement Lens Collar is specifically designed for the Nikon 300mm 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 6061T6 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.
Use of this lens collar with Arca flip lock mounts, while possible, will not yield optimal performance and is not recommend. Use with a Kirk quick release or mount an additional Arca plate to the bottom of the collar for Arca mounts.