This is the LB11-12-50, a 12.7 mm diameter Double-Concave Spherical Lens made from N-BK7 Schott glass. The lens, sourced from CeNing Optics, features a center thickness of 2 mm and an effective focal length (EFL) of -50 mm, making it suitable for a variety of optical applications.
The lens's geometry includes a first radius (R1) of -52.24 mm and a second radius (R2) of 52.24 mm, with no inner or outer radius specified. This particular lens is uncoated, which may affect its performance in certain applications, particularly those involving high-intensity light sources or specific wavelengths.
The LB11-12-50 is designed for use with a wavelength of 546.1 nm, and its spherical shape contributes to its wide range of potential uses. The lens is currently in stock and available for immediate use or integration into your optical system.
For more information, including detailed specifications and potential applications, please refer to the vendor's website, linked below.
http://www.cn-optics.com/products/Lenses_D_CV.asp