Thank you for viewing. Toshiba / Mazda 6G-B6 vacuum tube, with original box. Although the Mazda lettering is not on the outer box, the Mazda marking is printed on the glass part of the tube itself. We do not have measuring instruments or an operating environment, so the operation of this item has not been confirmed. This item has been stored for a long time in a cool, dark place, so it is offered as-is, for those who understand. Please check the condition in the photos. Everything shown in the photos is included. Thank you.