The Challenger Night Vision Scope is a new Gen1 tube based unit that has a state-of-the-art design and improved performance characteristics. At the core of the Challenger GS 1x20 is the unique combination of specially designed R-Contact optics and the  CF-Super Image Intensifier Tube, created specifically for each other such that they will not work with any other system.
The device is outfitted with a new five-lens eyepiece that minimizes distortion on the edges of the field of view and increases sharpness and contrast of the image. 
The device is equipped with an IR illuminator necessary for normal observation in moonless cloudy conditions.