The Type L-2B was a definitive edition to the light-zone category. It was standard USAF issue until replaced by the CWU 36/P jacket in the late 1970's. The essential differences between the L-2A and L-2B are colour and the way the size is format is indicated on the label: L-2B’s were changed to Sage Green from USAF BLUE, and the sizing format changed to S, M, L & XL. Size specs. were also changed to create a roomier fit, and the composition of the nylon outer fabric was changed to 2/2 heavy nylon twill from 1/3 twill. Additionally the lining material was changed to wool-and-rayon from a wool-and-nylon blend. MATERIAL :Mil spec. 2/2 Heavy Nylon Twill COLOUR :Sage Green LINING :Wool 35% Rayon 65% Double Face Brushed KNIT PARTS :Mil spec. 100% Wool ZIP :Crown Aluminium Auto Lock SNAP :Mil spec. Brass Black Oxidized LABEL :Tops Apparel Mfg. Co., Inc.