Popular transistors.

IRF840 MOSFET transistor.
Pinout. Datasheet.

Package: TO-220AB, 1-gate, 2-drain, 3 - sourse, 4-drain.
Type of IRF840 transistor: MOSFET
Type of control channel: N - Channel
Maximum power dissipation (PD):125W
Maximum drain-source voltage (VDSS): 500V
Maximum gate-source voltage (VGS): ±20V
Maximum continuous drain current (ID): 8 A
Maximum pulsed drain current (IDM):32 A
Maximum junction temperature (Tj): 175C
Rise Time (tR):37ns
Input Capacitance (Ciss):1300pF
Output Capacitance (Coss):310pF
Maximum drain-source on-state resistance (RDS): 0.85 Ohm
Forward Transconductance(gfs):4,9(min.)