The Tau WFOV Lens Locking Ring is designed to allow a WFOV Tau camera to be bulkhead-mounted. The outside of the lens holder provides M29 x 1.0 threads. By placing the lens through the clearance hole in a bulkhead, the locking ring attaches to the threads to secure the camera to the bulkhead. A Type 2 -025 O-ring should be used between the bulkhead and the Lens Locking Ring to achieve a weatherized seal. This O-ring is not available from FLIR, but is a standard O-ring sold by many suppliers.