The 808-0331-500 is a sub-miniature incandescent press-to-test indicator designed for back-of-panel mounting in a 15/32" clearance hole, featuring a red transparent lens and non-dimming mechanical shutter semi-blackout design. This indicator meets or exceeds the requirements of MIL-L-7961B and MIL-L-3661 military standards and is QPL approved by the Department of Defense. The assembly utilizes a T-1¼ bulb with midget flange base and incorporates a 3-terminal press-to-test circuit that allows operators to verify lamp functionality instantly by applying slight pressure to the lens holder without removing the assembly from the panel. The mounting bushing features 15/32–32 NS threading with a maximum panel thickness of 5/16" and a maximum projection of 7/8" back of panel. Materials include aluminum black anodized mounting bushing and lens holder, phosphor bronze internal-tooth lockwasher with white nickel finish, and brass terminals with hot tinned elongated slots. This indicator is ideal for safety-critical applications in military and industrial equipment where reliable lamp testing and visual indication are essential.