This Nitecore Blue filter is designed to be used with flashlights having a bezel diameter of 22.5mm. It will produce less disturbing light for dimer or dark environments by converting your light to blue. The filter comes with a very PC2805 durable plastic frame making it very impact resistant and long lasting. 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.