This product is a Protected Silver Plano-Convex Spherical Mirror, offered by EKSMA Optics. It is designed for use with a wavelength of 400nm and features a spherical shape with a diameter of 50.8mm and a thickness of 10mm at the center. The mirror's base shape is circular, and it has a protective silver coating on the front surface, identified as 'eks 0025protsil 4000'.
The mirror's geometry includes a 500mm radius of curvature (R1) and an effective focal length (EFL) of 250mm. The material used for this mirror is N-BK7 Schott, a popular choice for its excellent optical properties.
According to the vendor's information, this item is currently in stock and more details can be found on the EKSMA Optics website. The link provided leads to the specific page where this mirror is listed among other metallic mirrors offered by the vendor.