The Farnsworth 1P25 is a historic, military-grade infrared (IR) image converter tube heavily utilized during World War II in the United States’ very first night vision systems. Developed primarily to allow soldiers to see in total darkness using invisible infrared light, it served as the core optoelectronic component for the iconic M1 and M2 Sniperscopes mounted on the. 30 caliber M1 Carbine.