This part is a kind of semiconductor called EER28.

Function of this product has EER Cores.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

EER Cores ET-D AL-Value(nH/N’+25%): 1 kHz, 0.25v, 1 OOTs, 25+3”C R* (DIMENSIONS) EER28/28A EER28/34 ) 1 1 EER28/34A EER30/16 EER30/22 EER30/32 I ) 1 1 ) 28.5OkO.60 28.50+0.60 28.50+0.60 30.00~0.50 29.8OkO.80 29.8OfiO.80 33.00+0.50 34.20+0.80 I 1 ( 1 1 28.001rO.50 33.80+0.50 33.80_+0.50 16.00+0.30 21.80+0.40 31.60+0.60 34.6OkO.60 26.00f0.40 1 1 1 1 ) 11.40~0.30 11.40+0.30 11.40+0.30 20.00+0.30 9.50+0.30 9.50+0.30 13.80+0.25 10.80+0.30 1 I 1 I 1 21.80min 21.20min 21.80min 25.60min 22.00mrpI 22.oomin 24.50min 25.60min ( ) ) 9.90+0.30 9.9OkO.30 19.30+0.50 25.00+0.50 11 .QO?rO.20 ~---r10.6o?ro.40 I ~~~~~~ ~~$%~~~I 12.20+0.40 1 9.~&0.30--~122.00+0.6fl ~~9.90,0.;0-~~~[25.00_+0.50 I 1 EER30/35 EER34/26 ~2,50fo.~~--10.60_+0.30 I ~~~ ~2GGzTl 15.6OuQ.60 j [ ... ]

EER28 PDF Datasheet Download