This is a Plano-Concave Lens from Laser Components, designed with a base shape of a circle and a spherical geometry. The lens has a diameter of 25.4 mm and a center thickness of 2 mm. The effective focal length (EFL) of this lens is -50 mm, making it a negative lens. The inner radius is 0 mm, and the outer radius is also 0 mm, indicating a plano surface on one side and a concave surface on the other.
The lens is made of N-BK7 Schott, a popular optical glass known for its excellent optical properties. It is designed to work with a wavelength of 633 nm. The lens does not have any coating, as indicated by the empty 'coating' field in the item data.
The lens is in stock and available for immediate purchase. For more detailed information, you can refer to the datasheet provided by the vendor at https://www.lasercomponents.com/fileadmin/user_upload/home/Datasheets/lc-optics/substrates/plano_concave_lenses.pdf.