This is a Plano-Concave lens, a type of spherical lens, sourced from Qioptiq Photonics. The lens has a diameter of 12.7 mm and a center thickness of 1.5 mm. The effective focal length (EFL) of this lens is -50mm, making it a negative lens. This particular lens is designed to work optimally with wavelengths between 725nm and 1050nm.
The lens is made of N-BK7, a type of glass commonly used in optical applications due to its excellent optical properties. The lens's front and back surfaces are coated with qio bbar arb2nirnbk7, a broadband anti-reflection coating that reduces surface reflections and increases transmission.
The lens is mounted, making it ready for immediate use in optical systems. The item data does not provide specific details about the mount, but it can be inferred that it is suitable for the lens's dimensions and specifications.