New-Old-Stock (NOS) tube.

The 6211-A is a miniature, medium-mu twin triode for service in electronic computers. The electrical characteristics are essentially equivalent to those of the 5844. Unlike that tube, however, each section of the 6211-A has a separate cathode connection. ADditional features of this tube include a heater-cathode construction designed for dependable service under conditions of intermittent operation, and a cathode designed to maintain its emission capabilities after long periods of operation under cutoff conditions.

The 6211-A, when operated under approved conditions, will exhibit a life of greater than 10,000 hours, averaged over a 100 tube log, and based on the 10,000 hour end-of-life point shown under Special Tests and Ratings.