One pair Siemens & Halske gold pin CCa tubes made in Munich Germany in 1968. Same date code (see photo). Tyler at tctubes tested the tubes with Amplitrex AT1000 on October 2015, and said they "tested well". Test results on tube boxes (see photo). The tubes have not been used since then. Siemens & Halske CCa tubes are rare and considered by many to be the very best of the 6DJ8, 6922, 7308, CCa group. Brent Jesse (audiotubes.com) says: "whew, these babies are scarce/these gold pinned gems are about as good as it gets in 6DJ8-land/awesome audiophile tubes/ 10,000 hour heater life-expectancy". Brent lists these tubes from the 1960s at $299.00 per single tube. On the tube museum website (tubemuseum.org), CCa tubes from the 1950s and 1960s are said to be: "Rarest and most sought after CCa/ Most realistic sounding holographic soundstage, pure seductive magic/ Complex symphonic images emerge effortlessly".