This is a great matched pair of real selected-stock Mullard 12AX7/ECC83 tubes--Produced at Mullard's legendary Blackburn factory in the UK in the early 1960s, these 12AX7 tubes feature copper gridposts and extended cathode processing for extra detail and definition in the midrange as well as airy, extended treble. The early 1960s Mullard 12AX7 is world renowned as a VERY musical, lively 12AX7 that sounds so very natural and musical in any tube equipment. I bought these Mullards from Vintage Tube Services just over 10 years ago and used them for about 3 months, no more than 250-300 hours or so, in a preamplifier I no longer own. Keep in mind that these vintage Mullard tubes have an average lifespan of 5000 to 10,000+ hours! I verified their STRONG, basically new quality with a Hickock Cardmatic tester-- I got a result of 92/93 for the 1st tube and 91/94 for tube two, (out of 100 Gm points possible; note, all testers read differently and this result is for reference only)These are Vintage Tubes' "green tip MM phono grade 12AX7", which means they meet the rigorous standards set for Vintage Tubes Services super low noise/low microphonics Phono-grade 12AX7 tube; thus, they will match superbly with any moving magnet or high-output moving coil cartridge. These Mullard 12AX7 tubes were labeled as OEM-selected tubes for Bogen by Mullard. Like all early 1960s Mullard tubes, the white lettering on the glass is extremely fragile and wipes off easily; this pair's print is so-so; they clearly say "Mullard" but a portion of the lettering in "Bogen" and the 12AX7 designation has been wiped away. The discounted price of this pair reflects the slightly more smeared printing. STILL great tubes that have THOUSANDS of hours of life left, and offered here at an attractive discount. 7/10 for the smeared printing; electrically/functionally perfect. NO EXTRA CHARGE FOR PAYPAL! Just $4.95 for FULLY INSURED shipping to USA.