Neutral Density Filters are the reflective type of ND filters, which are used to control the light intensity. Coated chromel layer attenuates the light by mainly reflecting and partially absorbing. Our ND filters are designed to keep spectrally even performance especially in VIS range without altering the relative spectral distribution of the energy. Still they are available from UV through IR because the substrate material is fused silica. 6 kinds of attenuation rate are available.