HERE IS A VINTAGE NEW OLD STOCK RCA RADIOTRON 991 AUDIO VACUUM TUBE WITH A BRASS BASE. NEVER USED UNTESTED AS FAR AS I KNOW OTHER THAN AT MANUFACTURING PLANT. BOX TAB DATE IS (5-56), ALL ORIGINAL PACKAGING. ANOTHER VINTAGE TUBE FROM MY FATHER IN LAWS OLD AUDIO AND TV REPAIR AND SALES STORE INVENTORY. PLEASE VIEW ALL PICS AND READ MY PAST FEED BACKS OF ALL THE TUBES FROM THE SAME INVENTORY I HAVE SOLD. EVERYONE HAS BEEN PLEASED.