This part is a kind of semiconductor called MT3258.

Function of this product has N-Channel Power MOSFET.

Manufacturers : MOS-TECH

Image and pinout :

Some of the text within the PDF file :

 MT3258/B 1&KDQQHO9$3RZHU026)(7 )HDWXUHV ‡ Max RDS(on)=5m: at VGS =10V,ID =85A ‡ Fast Switching Speed ‡ Low Gate Charge ‡100% avalanche tested *HQHUDO'HVFULSWLRQ 7KLV1&KDQQHO026)(7LVSURGXFHGXVLQJ0267(&+ 6HPLFRQGXFWRU¶VDGYDQFHG3RZHU7UHQFKSURFHVVWKDWKDV EHHQ HVSHFLDOO WDLORUHG WR PLQLPL]H WKH RQVWDWH UHVLVWDQFH DQG HW PDLQWDLQVXSHULRUVZLWFKLQJSHUIRUPDQFH $SSOLFDWLRQV ‡ '&'&SULPDUEULGJH ‡ '&'&6QFKURQRXVUHFWLILFDWLRQ ‡3RZHU0DQDJHPHPHQWIRU,QYHUWHU6VWHPV G DS G  D S TO-252 D G Absolute Maximum Ratings Symbol Parameter Common Ratings (TC=25°C Unless Otherwise Noted) VDSS VGSS TJ TSTG IS Drain-Source Voltage Gate-Source Voltage Maximum Junction Temperature Storage Temperature Range Diod [ ... ]

MT3258 PDF Datasheet Download