Check the listing for details. 80 METER CW 2 PACK FOR OLD BOATANCHOR TUBE TRANSMITTERS (HC49/U CRYSTALS). Condition: Used. Listed at 17.45 USD. YOU ARE PURCHASING ONE LOT OF TWO 80 METER CRYSTALS IN USED FT-243 STYLE HOLDERS. ONE EACH, 3550 AND 3576 KHZ FUNDAMENTAL FREQUENCIES. THESE HAVE THE LARGER, HIGHER POWER VERSION OF THE HC49 CRYSTALS (HC49/U). I SIMPLY REMOVED THE OLD OUT OF BAND MILITARY CRYSTAL ELEMENT AND SOLDERED IN THE HC49/U TALL VERSION OF THIS WELL KNOWN QRP CRYSTAL, WHICH CAN ALSO BE USED IN MANY, IF NOT MOST TUBE CIRCUITS. AS YOU CAN SEE IN THE SECOND PHOTO THE TALL VERSION IS MORE THAN 3X THE SIZE OF THE SMALLER HC49/S AND CAN HANDLE MORE CURRENT. WHEREAS THE SMALLER HC49/S CRYSTALS WILL SOMETIMES WIMP OUT, THE TALLER VERSION TYPICALLY PERFORMS JUST AS WELL, IF NOT BETTER THAN A STANDARD CRYSTAL WITH THE ORIGINAL FT-243 ELEMENT. I'VE USED THESE 49/U TALL CRYSTALS IN MY LITTLE 15 WATT 6V6 AMECO AC-1 TRANSMITTER, AND THEY WORK GREAT, NO ISSUES. THE FREQUENCIES, AS MARKED, ARE APPROXIMATE AND MAY VARY PLUS OR MINUS 1 KHZ, DEPENDING ON CIRCUIT LOADING. SHIPPING TO THE UNITED STATES ONLY (eBAY INTERNATIONAL SHIPPING OK).