Abstract: An LED for use with a medical diagnostic instrument having an adapter disposed between an instrument head and a hand-grippable handle, the LED being removably attachable in relation to the adapter in order to permit selective replacement of the LED, as needed. The LED is situated in order to provide mechanical and electrical interface with at least one of the adapter and the instrument, thereby enabling the adapter and the LED to convert the illumination source of the instrument selectively between an incandescent light source and the LED. The adapter matches a polarity between the LED and a power supply that is specifically intended for powering an incandescent light source.

Abstract: A medical diagnostic instrument includes a housing containing at least one battery and a light source, such as a lamp, for illuminating a medical target. A switch includes a movable member that selectively moves at least one of the battery and the lamp into and out of electrical connection with the other. The instrument is preferably fabricated from a diecast or an extrusion process wherein a thin plastic sleeve member having text and/or graphic materials can be shrink fitted onto an extruded handle.