Pivoting Inspection Mirror Made to Federal Spec GGG-M-350B. NSN 5120-00-278-9926. Approx. 10" long, mirror head is 1.5" x 1.25". Has a locking hinge so you can keep the pivot at a desired angle while you work. Originally developed for aircraft inspection. I use one of these to inspect the circumference of solder and braze joints. GTBD34