this is an N-Channel MOSFET in TO251 package, designed based on Plannar technology, optimized for high voltage applications. With a maximum drain-source voltage (VDS) of 650V and a maximum drain current of 4A, this MOSFET is suitable for high voltage power switching and control applications. IRFU420PBF-VB has a higher threshold voltage and on-resistance, making it suitable for use in scenarios that require high voltage handling and lower current.