The CLB-2050-300NM from Laser 2000 (UK) Ltd. is a Optical Lens with Wavelength Range 400 to 700 nm, Focal Length -30 cm(-300 mm), Center Thickness 3.7 mm, Radius 15.57 cm(155.7 mm), Edge Thickness(ET) 4 mm. More details for CLB-2050-300NM can be seen below.