Hi, According to my information, the OAW-1 tube tester is described as: OAW-(1) Transmitting tube tester, for peak emission & cutoff of, e.g., 15E, 227, 327, VT-90 (8011) tubes. 10x13x18", 50 lbs; 115/60. Navaer 08-5S-103 (OAW); Navships 900,722 (OAW-1). David, W1TDD