This is a WBF2540 Barium Fluoride (BaF2) round window, available from Knight Optical. With a diameter of 25.4 mm and a thickness of 4 mm, it is a flat window type, designed in a circular base shape. The window is made of Barium Fluoride, a material with the ID 'baf2 cgdm'.
The window is uncoated and designed to operate at a wavelength of 633 nm. It features a thin lens shape, making it suitable for various optical applications. The window's geometry, including its diameter and thickness, make it a versatile option for users in need of a robust and reliable optical component.
According to the vendor's information, this item is currently in stock and can be purchased directly from Knight Optical's website. The link to the product page is provided for your convenience. The window's uncoated surface allows for customization upon request, making it a flexible choice for a variety of optical systems.