Tubes made by Matsushita to Haltron brand .Tested quality both tubes at 92 . On my B&K Dyna Jet 606 tester calibration that means strong near new . No shorts or grid emission ." Matsushita used the Mullard EL34 tooling to produce these 6CA7 / EL34 tubes making them the closest thing to the real Mullard Xf2 single "halo" getter version. These EL34's were produced in Japan's Matsushita plant after the Mullard plant in Blackburn, England ceased production of the EL34 tube type.