This is a Plano-Convex Spherical Lens, type N-BK7, with a diameter of 16 mm and an effective focal length (EFL) of 20 mm. The lens is sourced from Knight Optical and is currently in stock. The lens features a plano surface on one side and a convex surface on the other, with a center thickness of 5.3 mm and an edge thickness of 1.5 mm. The inner and outer radii are both 0 mm, indicating a symmetrical curvature.
The lens is made of N-BK7, a popular optical glass from Schott, known for its excellent optical properties and versatility. It is designed to operate at a wavelength of 587.6 nm. The lens does not come with any coating, as indicated by the empty 'coating' field in the item data.
For more information, you can refer to the vendor's website through the provided weblink. The link has been verified and is currently valid, leading to a page where the lens is listed as in stock.