MIL spec vintage 12AX7 preamp audio tube made by Mullard in Blackburn / UK (code I63 / B9F2) with ring getter and ribbed plates. Removed from old military ampilfier equipment.
Tested, electrically good on my Funke W19S. Shipping worldwide from Germany via registered air mail, PayPal welcome. Please have a look also to my other items for more tubes and radio parts.