This is a Plano-Convex Lens, a type of spherical lens, sourced from Standa. It is a circular lens with a diameter of 50.8 mm and a base shape of Plano-Convex. The lens is uncoated, which means it does not have any additional layers to enhance or alter its optical properties.
The lens has a thickness of 4 mm at the edge and 5.5 mm at the center. The effective focal length (EFL) of the lens is 400 mm. The radius of curvature (R1) is 206.68 mm, and the inner and outer radii are 0 mm.
The lens is made of n-BK7 Schott, a type of optical glass known for its excellent optical properties. The wavelength for this lens is 546 nm. This lens is in stock and available for immediate purchase.
For more information, please refer to the vendor's website at http://www.standaphotonics.com/lenses/plano-convex-lenses.php.