From Manufacturer
The Acratech Nodal Rail with Level Quick Release Clamp makes it possible for you to adjust your camera's position, front to back, to position the lens nodal point over the center of rotation for accurate stitched panoramic images. It has adjustable stops that can be preset to the nodal point of two different focal lengths.
Easily holds over 25 lbs
Weighs less than 0.5 lb with the quick release clamp
Indexable quick release clamp can be rotated in 90 degree increments
Double dovetail for added versatility
Precision machined aluminum
Compatible with Arca Swiss, Acratech, Kirk, Arca, R.R.S., and many other QR plates
Satin black anodized finish
Laser-engraved scale markings
Long-lasting stainless-steel hardware
Made in U.S.A.