The Challenger GS 1x 20mm is a multi-functional night vision device. The Challenger GS is suitable for a number of applications. It can be used as a night vision monocular, night vision goggles (if set up on a Head Mount; the device can be used either for the right or the left eye), or as a night attachment for a daytime rifle scope. The body of the device is hermetically sealed which enables use in inclement weather (fog, heavy shower, dusty environment, sand storm etc.). The device and the built-in IR illuminator are switched on/off with a single switch. The design of the switch prevents the IR illuminator from accidental activation (to avoid disclosure of the observer).