These blinker gauges were located at each crewman's station for high altitude, non-pressurized WWII aircraft. At a glance, he could see if he had oxygen flow. (If not, portable oxygen must be used.) Manufactured by Delco Radio Division of General Motors Corporation, USA. New old stock. These gauges are in new (mint) condition. This is a stock photo. The actual item you will be receiving will still be in its unopened, hermetically sealed, long-term storage packaging. Museum quality. Made in the USA.