!! Attention the article is no longer available !! the red filter is particularly suitable for humans due to the adaptation of the human eye. Wildlife observation can also be an advantage with the filter, as many animals are less able to perceive the red color. No tools are required for assembly, you just have to attach it to the lamp head. The rubber sleeve keeps the color filter firmly on the flashlight. It is compatible with many flashlights with a head diameter of 63 - 65 mm.