Multipurpose passive thermal target 15x15cm with 1cm grid lines for precision zeroing of your thermal optic. The thermal targets use the natural light and work night and day and in all environmental conditions. These targets provide high clarity and detail. A passive thermal target works with no additional power source. To create the contrast image the target reflects thermal energy of the environment. So, the cooler sky temperature reflects in the thermal target, as in a mirror. Therefore, the target appears cold in contrast to the warmer trees, buildings, etc. in its background. It is recommended to attach the target to a flat surface at an angle of ten or more degrees from vertical so that it reflects the colder sky. When a thermal device uses White-Hot palette, the passive target is black. In Black-Hot palette the passive target is white. Features: Passive thermal targets, no heat source neededMade from a material that has natural thermal contrastAllows for easy zeroing of the thermal rifle scope1cm grid for easy correction of point of impactWorks in any weather at day and nightComes as a pack of 25 and 50 pcs AGM Global Vision AGM Thermal Targets 50pack 633150S1