This listing is for two NOS Western Electric 717A radio vacuum tubes. These were purchased by the U.S. Army Signal Corps during World War II. These unusual tubes, sometimes referred to as "mushroom" or "doorknob" tubes were developed for use in radio receivers operating at VHF frequencies. They were later used in some commercial FM radio receivers.These tubes are triodes with octal bases. The shape of the tube resulted from need to keep internal leads and dimensions as small as possible. I tested these tubes on my Knight tube tester, with the results shown in the last two photos. These tubes will be shipped in their original boxes which are shown in some of the photos. I will pack these tubes carefully with bubble wrap and plenty of cushioning to make sure they reach their destination safely. I ONLY SHIP TO ADDRESSES IN THE UNITED STATES. NO INTERNATIONAL SHIPPING. All sales are final unless I have misrepresented this item in my description or photos.