The Nitecore NFD40 white filter is designed to be used with flashlights having a bezel diameter of 40mm. It will convert your normal light to a soft uniform light scattering angle that increases exposure. The filter comes with a very flexible rubber frame making it very impact resistant and durable. The lens is also made of glass and finished with an anti-reflective coating on both side to disperse light with great clarity and to easily tolerate high heat as well.