This part is a kind of semiconductor called EL34.
Function of this product has OUTPUT PENTODE PEDTHODE DE SOTRIE ENDPENTODE.
Manufacturers : NXP
Image and pinout :

Some of the text within the PDF file :
page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 EL34 sheet 1 2 3 4 A B C D E F G H I J K FP date 1958.02.02 1958.02.02 1956.02.02 1956.02.02 1949.10.10 1949.10.10 1952.02.02 1952.02.02 1951.06.06 1951.06.06 1951.06.06 1951.06.06 1951.06.06 1951.06.06 1951.06.06 1999.02.16 [ ... ]
EL34 PDF Datasheet Download
