12SH7 / VT-288 JAN CRC
Top of the line octal based pentode tubes manufactured for US military by world renowned RCA. These metal tubes are printed in white JAN 12SH7 VT-288 MADE IN U.S.A. with old style RCA logo, and coded K6E or H5E. Brown military boxes are printed U.S. ARMY U.S. NAVY MFGD. BY RADIO CORPORATION OF AMERICA, different contract numbers and 1940's dates. Some boxes are also printed LINK RADIO CORP. N.Y.C. or ADMIRAL CORP. CONT. 62370, and stamped in German GEPRUFT.