Abstract: An illumination device, for example, a flashlight includes an adjustable beam focus assembly to change the relative position of the lamp bulb to the reflector to alternately provide a narrow focused or wide beam being emitted from the device. The adjustable beam focus assembly includes a resilient blade supporting the lamp bulb extending through an opening in a reflector of the device. Beam focusing is achieved by flexing the blade upon application of a displacing force to the base of the bulb by a cam or to the blade itself using a plunger.