One 1000nm IPL Colour Glass Filter. This is a replacement filter for use with IPL cosmetic and medical treatment machines. The filters are usually located inside the applicator itself. Long Pass Colour glass filters work by attenuating the shorter wavelength, whilst transmitting the longer IR wavelengths. The blocking of the UV light is by absorption and not reflection.Material: Schott RG1000 Colour Glass. Length: 55mm Width: 20.75mm Thickness: 2.5mm. T=50% @ 1000nm +/- 10nm