This vintage vacuum tube from General Electric is a rare find for collectors and enthusiasts of vintage electronics. The model 5AS4A is a testing tube that has been tested to ensure it is in working condition. It is a unit type vacuum tube that was manufactured in the United States and is a great addition to any vintage audio or video collection. The tube is from the brand GE and is a perfect replacement for any old or broken tubes. This vacuum tube is a great investment for those who want to preserve the quality of their vintage electronics.