Here is an image showing the pin diagram of this transistor.
Classification of hFE
The KSB744A-O transistor can have a current gain of 100 to 200. The gain of the KSB744A will be in the range from 60 to 320, for the KSB744A-R it will be in the range from 60 to 120, for the KSB744A-Y it will be in the range from 160 to 320.
Complementary NPN transistor
The complementary NPN transistor to the KSB744A-O is the KSD794A-O.
SMD Version of KSB744A-O transistor
The NZT660 (SOT-223) is the SMD version of the KSB744A-O transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.
Replacement and Equivalent for KSB744A-O transistor