This part is a kind of semiconductor called K1881.

Function of this product has 2SK1881.

Manufacturers : Fuji Electric

Image and pinout :

Some of the text within the PDF file :

2SK1881-L,S F-III Series > Features High Current Low On-Resistance No Secondary Breakdown Low Driving Power High Forward Transconductance N-channel MOS-FET 60V 0,07Ω 20A 45W > Outline Drawing > Applications - Motor Control - General Purpose Power Amplifier - DC-DC converters > Maximum Ratings and Characteristics - Absolute Maximum Ratings (TC=25°C), unless otherwise specified Item Drain-Source-Voltage Drain-Gate-Voltage (RGS=20KΩ) Continous Drain Current Pulsed Drain Current Gate-Source-Voltage Max. Power Dissipation Operating and Storage Temperature Range Symbol V DS V DGR ID I D(puls) V GS PD T ch T stg Rating 60 60 20 80 ±20 45 150 -55 ~ +150 Unit V V A A V W °C °C > Equivalent Circuit - Electrical Characteristics (TC=25°C), unless otherwise specified Item Drain-Source [ ... ]

K1881 PDF Datasheet Download