051-0137-203 is a clear convex lens cap designed for the Dialight 378 Series indicator base assembly. It features a translucent clear optical material that allows full light transmission while providing environmental protection. The lens cap is compatible with the S6 double contact bayonet base and includes a watertight screw-on design that meets MIL-L-3661C requirements, making it suitable for demanding military and industrial applications. The convex lens design provides optimal light distribution and is commonly used in ground vehicles, power distribution centers, aircraft cockpits, naval vessels, and surveillance systems where reliable visual indication is critical.