This part is a kind of semiconductor called K2611B.

Function of this product has Silicon N-Channel MOSFET.

Manufacturers : Winsemi

Image and pinout :

Some of the text within the PDF file :

K2611B Product Description Silicon N-Channel MOSFET Features � 11A,900V, RDS(on)(Max1.10Ω)@VGS=10V � Ultra-low Gate charge(Typical 66nC) � Fast Switching Capability � 100%Avalanche Tested � Improved dv/dt capability � RoHS product General Description This N-Channel enhancement mode power field effect transistors are produced using Winsemi's proprietary, planar stripe ,DMOS technology. This advanced technology has been especially tailored to minimize on-state resistance , provide superior switching performance, and withstand high energy pulse in the avalanche and commutation mode. These devices are well suited for high efficiency switch mode power supplies. Absolute Maximum Ratings Symbol Parameter VDSS ID Drain Source Voltage Continuous Drain Current(@Tc=25℃) Continuo [ ... ]

K2611B PDF Datasheet Download