This is a 091-3125FR-50 12.7 mm Dia. UVFS Enhanced Silver Plano-Concave Spherical Mirror, with a thickness of 6mm and a wavelength range of 600-1100nm. The mirror is sourced from the reputable vendor, EKSMA Optics, and is currently in stock.
The mirror is a Curved Mirror (Concave) type, with a base shape of Circular. It has a diameter of 12.7mm and a thickness edge of 6mm. The effective focal length (EFL) of the mirror is -25, and the radius of curvature (R1) is -50.
The mirror is made of UVFS material, specifically UVFS Mal- 1965. The coating on the front surface is EKS Enhsil600110045, which is an enhanced silver coating. The mirror's shape is Spherical.
For more information about this mirror, please refer to the vendor's website at https://eksmaoptics.com/optical-components/metallic-mirrors/enhanced-silver-mirrors/.