Amazon.com : Selens 15.8x19.7in Pack of 3 Transparent Color Correction Lighting Gel Filter Plastic Sheet in 3 Colors for Photo Studio Strobe Flashlight (Red, Green,Blue) : Electronics
Nitecore 32mm Red Flashlight Filter for P20iX P20i and P20i UV
Nitecore Red Filter for 25.4mm Flashlight NFR25 B&H Photo Video
Making a red lens for flashlight; a red beam for night vision. - YouTube
Olight Flashlight Filter Red - Fits M2X-UT, M3X, SR51, SR52
Fenix PD36R 1600 Lumen rechargeable CREE LED tactical Flashlight, red – EdisonBright