Original Cap, Hot Weather OG-507. Vietnam war type cap worn by the Army and Air Force. These are orignial unissued surplus caps that have been sitting in a warehouse for almost 40 years! All are post war dated and from different manufacturers. They have a leather or leatherette sweat band. They are the same type issued during the Vietnam war. 50% Polyester 50% Cotton in Excellent Condition! Two Sizes available: Small (6-7/8) and Large (7-3/8). Larger Sizes are $15.00 more.