This is a Plano-Concave Lens from Standa, a renowned vendor in the optical industry. The lens, which has a base shape of a circle, is designed with a spherical geometry, featuring a diameter of 12.7 mm and a thickness that varies from 3 mm at the edge to 2.8 mm at the center.
The lens is intended for use with a wavelength of 355 nm and has an effective focal length (EFL) of -200 mm. The inner and outer radii are 0, and the curvature (R1) is -95.22 mm. The lens material is UVFS Mal- 1965, and it does not come with any coating.
The lens's web link status is valid, and it is currently in stock, according to the vendor's website. For more information about this lens and similar products, you can visit the vendor's website at http://www.standaphotonics.com/lenses/plano-concave-lenses.php.