The 800-1030-0334-504 is a sub-miniature incandescent press-to-test indicator designed for back-of-panel mounting in a 15/32" clearance hole, featuring a blue transparent lens and non-dimming operation. The assembly meets or exceeds MIL-L-7961B and MIL-L-3661 requirements and utilizes a T-1¼ bulb with midget flange base. The indicator features a 3-terminal press-to-test circuit that allows operators to verify lamp functionality by applying slight pressure to the lens holder, which breaks the normal circuit and engages a test circuit without requiring lamp removal. The mounting bushing is 15/32–32 NS threaded with a maximum panel thickness of 5/16", and the assembly incorporates aluminum components with black anodize finish, phosphor bronze internal-tooth lockwasher with white nickel finish, and brass terminals with hot tinned elongated slots. This design provides positive safety factors for critical applications in aerospace, military, and industrial control systems where lamp status verification is essential.