EOTech's X640 thermal imager relies on infrared light (heat) emissions to detect people, animals, and vehicles at great distances. It can be used day or night in any weather conditions because it has the highest electro-optical thermal sensitivity available. It provides impressive 640 x 480 resolution with a 30 Hz refresh rate, with 2x/3x/4x zoom and the ability to detect activity up to 1,100 yards away, making it perfect for public safety, first responders, security operations, and hunting (where local laws allow). Offers user-selectable white= hot, black = hot, and three separate color modes. There's an NTSC video port for simultaneous recording, and customizable camera features with the included interface software. You'll get up to 5 hours run time with two AA lithium batteries at room temp and nominal settings. The compact, rugged housing is submersible to a depth of 3 ft. and shock resistant up to a 3 ft. drop. 24° model offers a 24° x 18° (height x width) field of view (FOV), while18° model has an 18° x 13.5° FOV.