This is a G313374329 12.7 mm Dia. N-BK7 Double-Concave Lens, specifically designed for use with a wavelength of 588nm and featuring an effective focal length (EFL) of -50mm. The lens is sourced from Qioptiq Photonics, a renowned vendor in the field of precision optics.
The lens is a Spherical Lens of the Sub Type Spherical Lens (Concave-Concave), with a base shape of Circular. It has a diameter of 12.7mm and a center thickness of 1.5mm. The lens's first radius of curvature (r1) is -52.33, and the second radius of curvature (r2) is 52.33. The lens's inner and outer radii are both 0.
The lens is made of N-BK7 Schott, a popular material in the optical industry due to its excellent optical properties. The lens is coated with Qio Hp Nbar Arhs-Yag on both the front and back, providing anti-reflective properties that enhance its performance.
The lens's web links are valid and it is currently in stock, making it readily available for your optical needs.