This part is a kind of semiconductor called 2N3546.

Function of this product has Small Signal Transistors.

Manufacturers : Central Semiconductor

Image and pinout :

Some of the text within the PDF file :

Small Signal Transistors TO-18 Case (Continued) TYPE NO. DESCRIPTION BVCBO BVCEO BVEBO ICBO @ VCB (V) (V) (V) (µA) (V) MIN MIN MIN MAX *ICES **ICEV hFE @ IC @ VCE VCE (SAT) @ IC Cob fT NF ton (mA) (V) (V) (mA) (pF) (MHz) (dB) (ns) MIN MAX MAX MAX MIN MAX MAX toff (ns) MAX 2N2896 NPN AMPL/SWITCH 140 2N2897 NPN AMPL/SWITCH 60 2N2906A PNP AMPL/SWITCH 60 2N2907A PNP AMPL/SWITCH 60 2N2952 NPN AMPL/SWITCH 60 2N3009 NPN SAT SWITCH 40 2N3011 NPN SAT SWITCH 30 2N3012 PNP SAT SWITCH 12 2N3013 NPN SAT SWITCH 40 2N3014 NPN SAT SWITCH 40 2N3073 PNP AMPL/SWITCH 60 2N3115 NPN AMPL/SWITCH 20 2N3116 NPN AMPL/SWITCH 20 2N3117 NPN AMPL/SWITCH 60 2N3121 PNP AMPL/SWITCH 45 2N3135 PNP AMPL/SWITCH 50 2N3136 PNP AMPL/SWITCH 50 2N3209 PNP SAT SWITCH 20 2N3210 NPN SAT SWITCH 40 2N3241A NPN AMPL/SWITCH 30 [ ... ]

2N3546 PDF Datasheet Download