Machined from a solid block of 6061-T6 aluminum and fully-compatible with all RRS dovetail quick release systems, the B22 fore-aft plate is designed for use with collared telephoto lenses as well as some camera bodies. They feature simple, square anti-twist flanges to prevent twisting between the plate and camera body or lens foot. The quick release plate is equipped with a custom-machined 3/8-16 TPI captive-style mounting screw which threads into the tripod mounting socket of a camera body or lens foot. Really Right Stuff B22 SOAR QR Fore-Aft Plate for Swarovski Spotting Scopes RRS-9000468