Original production Mil. Spec. twin triode tubes manufactured for the US Armed Forces by renowned General Electric. These 9 pin miniature glass amplifier tubes come with black plates, thick mica supports, and top getters. They are printed in green with GE logo, JAN 5687WB MADE IN U.S.A. with 1970 or 1980 production codes. They are also glass etched 5687WB with various dot codes.