The K12 replaced the very popular K10 and K10+ keyers which were designed over ten years ago. The K12 shares the same pinout with the K10's so you can easily upgrade your existing keyer and enjoy some great enhancements. The new K12 has non-volatile EEPROM memory, when you remove power it retains messages and settings ! No more keep alive battery. Six memory slots are supported along with many new embedded commands. In addition to HSCW support the K12 provides QRSS for VLF beacon work. The K12 is no longer recommended for new designs, the K16 is a much better keyer for just a few dollars more. We still sell the K12 for those who need a replacement or spare.