The 271-0171, also known by type designation LC34CN2/DO2, is a light seal cap for the 271 series indicator base assembly. This component features a black top, a clear filter, and an opaque black light seal washer. It is designed for use with military-compliant indicator assemblies that mount in a 15/32-inch clearance hole and accept T-1 3/4 Midget Flange base bulbs. The cap's resilient washer prevents light loss at the panel front, making it ideal for demanding applications like military vehicles, aircraft cockpits, and naval control panels.