A lamp, such as for truck trailers and/or tractors, is provided with LEDs mounted to a circuit board placed in a housing. The housing is thereafter partially filled with a liquid resin material and a lip portion of a lens member is pressed into the resin into contact with the circuit board. The resin material is cured with thermally conductive particles suspended therein for conducting excess heat to the outer aluminum housing and the outer environment. A hermetic seal is formed by the resin material between the lens member and the LED bearing circuit board. The lens member has a series of parallel, elongated lens ribs providing constant optics while allowing additional LEDs to be positioned in a row behind a lens rib. The lens member is completely recessed within the housing for enhanced protection from mechanical damage thereto.