This is an accessory for Fenix flashlights which own outstanding filtration ability to maintain strong red, blue, or green light, and it could be used as signal lamp or weft when necessary. Features- Red: Preserves nigh vision Improves night vision visibility Assists in spotting game without fear of being detected Uses a toughened ultra-clear glass lens with anti-reflective coating that provides heat resistanceand maximum light penetrability Anti-roll design, easy to attach, easy to remove This bundle includes EdisonBright Battery Case