Energizer Halogen Flashlight

This is now presumably out of date since LED lights are available that put out nearly as much light but for much less energy consumption.  Some of the new LED lights might even match or outperform the light output of halogens.  This is now a collectible light.

It uses 2 D Cell Batteries and is a basic design now superseded with a whole new array of lights that perform multiple duty as flashers, safety sticks, and area lights.  Hurray for the march of science and technology.