The CLB-2050-400PM from Laser 2000 (UK) Ltd. is a Optical Lens with Wavelength Range 400 to 700 nm, Focal Length 40 cm(400 mm), Center Thickness 4 mm, Radius 20.76 cm(207.6 mm), Edge Thickness(ET) 3.8 mm. More details for CLB-2050-400PM can be seen below.