This is an excellent matched pair of early 1960s production, selected-stock Mullard 12AX7/ECC83 tubes that feature copper gridposts and legenday Mullard quality for extra detail and definition in the midrange, plus airy, extended treble, and the utmost in natural/musical sonics. I bought these Mullards from Vintage Tube Services just over 10 years ago and used them only briefly (about 150 hours) in a preamplifier I no longer own. I verified their STRONG, basically new quality with a Hickock Cardmatic transconductance, or "Gm", tube tester-- I got a result of 96/93 for tube one and 94/98 for tube two (out of 100 Gm points possible; note, all testers read differently and this result is only for reference)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 Fisher 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 much better than most and is largely intact-- Great tubes with THOUSANDS of hours of outstanding sound reproduction left in them. 8/10 only for the minor lettering smear; very nice tubes. NO XTRA CHARGE FOR PAYING WITH PAYPAL! Shipping is $4.95 to USA.