A few of the retired Swiss Army knives from Victorinox include a red LED light. The light runs on a single, small, replaceable battery that is stored in the shell. It's an extremely handy little light, sufficient for finding a key hole, or reading small amounts of text at night. The red light is not as bright as newer white LEDs, but it has less impact on your dark vision, and the battery lasts much longer.
Uses: To use the red LED light, press the "cross" logo on the knife body.