The 65-876 is a 30 mm diameter, 4 mm thick flat window made from UVFS material with a Mal-1965 index. This window is designed to protect optical systems and is sourced from the reputable vendor, Edmund Optics. The item's wavelength is 587.6 nm, and it features a UV-AR coating on both the front and back surfaces, which covers the spectrum from 250 to 425 nm. This coating is part of the standard curve offered by Edmund Optics, ensuring high-quality performance. The window's thin lens shape and circular geometry make it suitable for a wide range of applications. According to the vendor's information, this item is currently in stock, making it readily available for immediate use.