This is the FS-px-50.8-304, a 50.8 mm diameter Plano-Convex lens made from UVFS material, sourced from Alkor Technologies. The lens is uncoated and has a focal length of 304.8mm (EFL).
The lens geometry is characterized by a thickness of 2.5mm at the edge and 4.8mm at the center. The inner radius is 0, while the outer radius is not specified, indicating a potentially infinite radius. The lens's shape is spherical, and it is designed to operate at a wavelength of 587.6nm.
The FS-px-50.8-304 is a part of the Fused Silica lenses catalog offered by Alkor Technologies, and it is currently in stock, as indicated by the "weblink status" field. For more detailed information, you can refer to the vendor's website through the provided weblink.