This is a WZN2504 Zinc Selenide (ZnSe) Standard Round Window, available from Knight Optical. The window has a base shape of a circle with a diameter of 25 mm and a thickness of 4 mm. It falls under the category of a Flat Window and features a Thin Lens shape.
The window is made of Zinc Selenide, a material with the material ID znse marple-1964. This material is known for its excellent transmission properties in the infrared region, making it suitable for applications involving infrared radiation.
The window is coated with a coating known as kni znse-ai114 on both the front and back surfaces. This coating is an Anti-Reflection (AR) coating designed to reduce reflection and increase transmission at a specific wavelength of 10600 nm.
According to the vendor, Knight Optical, this item is currently in stock and can be purchased directly from their website using the provided weblink. The weblink has been verified and found to be valid at the time of writing.