Made by Viewlex, Inc. Printing on the barrel: "PRECISION LENS MADE IN JAPAN 3" E.F. f/2.8 LUXTAR I-H ANASTIGMAT" Barrel is 42mm diameter by 100mm long. Clear lens diameter is 27mm diameter. Coated optics. 3 inch effective focal length, f/2.8. These may be rare as our searches only find the f/3.0 model. Unused.