This is a Plano-Concave Lens from Standa, a renowned vendor in the optical industry. The lens, which is part of the Spherical Lens category, is designed with a base shape of Circular and a Sub Type of Plano-Concave. The lens has a diameter of 12.7 mm and a thickness edge of 3 mm, while the thickness center measures 2.8 mm. The effective focal length (EFL) of this lens is -250 mm, indicating its diverging nature.
The lens's inner radius is 0, and the outer radius is also 0, which is typical for Plano-Concave lenses. The material ID for this lens is UVFS MAL-1965, and it is designed to work with a wavelength of 355 nm. The lens's shape is spherical, and it does not have any coating, as indicated in the item data.
For more information about this lens, including its availability and potential applications, you can refer to the vendor's website at http://www.standaphotonics.com/lenses/plano-concave-lenses.php. The link is valid and indicates that the lens is in stock, making it readily available for your optical needs.