This part is a kind of semiconductor called ECC81.
Function of this product has Double Triode 1955.
Manufacturers : Philips
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 ECC81 sheet 1 2 A B C D E F G H I J K FP date 1955.03.03 1955.03.03 1951.06.06 1951.06.06 1955.01.01 1955.01.01 1955.01.01 1955.01.01 1951.06.06 1951.06.06 1951.10.10 1951.10.10 1951.10.10 1999.02.16 [ ... ]
ECC81 PDF Datasheet Download
