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 -80 mm, making it a negative lens. The inner radius is 0 mm, and the outer radius is also 0 mm.
The lens is made of UVFS material with the ID 1965, and it is designed to work with a wavelength of 248 nm. The lens does not have any coating, as indicated in the item data.
The vendor for this lens is Laser Components, and the link provided leads to a datasheet with more technical information. According to the vendor, this item is in stock and the link is valid.