The FS-w-25.4-2 is a circular, flat window type optical element, sourced from Alkor Technologies. This window, with a diameter of 25.4 mm and a thickness of 2 mm, is made of UVFS material, specifically identified as UVFS Mal- 1965.
The item is designed for use with a wavelength of 633 nm and features a thin lens shape. The coating for this window is unspecified, indicating that it is likely uncoated. According to the vendor's website, this item is currently in stock, ensuring quick delivery upon order.
For more detailed information, including technical specifications and purchasing options, please refer to the vendor's website at http://www.alkor.net/FusedSilica_windows.html.