OptoSigma's FNDU-25C02-5 is a 25 mm diameter, unmounted Neutral Density Filter, designed for use in the ultraviolet spectrum. This filter is part of the UVFS series, identified by the material ID [uvfs mal- 1965].
The filter features a reflective neutral density coating, denoted as 'opt fndu-5' on both the front and back surfaces. This coating is designed to reduce the intensity of ultraviolet light, specifically within the wavelength range of 200-400nm, without altering the color balance of the light passing through it.
The filter has a thickness of 2mm, which is considered 'thin' in lens terminology. This thinness can be beneficial in certain applications where space is limited or when stacking multiple filters.
The FNDU-25C02-5 is currently in stock and available for purchase through the OptoSigma website. For more information, including pricing and detailed specifications, please refer to the provided weblink.