ND204B 50 mm x 50 mm; Unmounted Reflective ND Filter; Optical Density 0.4

The ND204B is a Neutral Density Filter, offered by Thorlabs, with a catalog number of ND204B. This filter is unmounted and has a rectangular base shape, making it suitable for a variety of applications. The filter is made of N-BK7 Schott material, a high-quality borosilicate glass known for its excellent optical properties.

The ND204B has a thickness of 2 mm and dimensions of 50 mm in width and 50 mm in height. It is coated with THo ND04 on both the front and back, providing a neutral density of 0.4. This coating ensures consistent light reduction across the visible spectrum, making it an ideal choice for applications requiring controlled light intensity.

The filter's shape is thin lens, which is designed to minimize optical aberrations and ensure high-quality imaging. The ND204B is currently in stock and available for purchase through the provided weblink. This filter is a reliable and versatile option for those seeking a high-quality Neutral Density Filter.