. . . designed for driver circuits, switching, and amplifier applications.
These high-performance plastic devices feature:
   
Features
• Low Saturation Voltage − VCE(sat) = 0.6 Vdc (Max) @ IC = 1.0 Amp
• Excellent Power Dissipation Due to Thermopad Construction -
    PD = 30 and 40 W @ TC = 25°C
• Excellent Safe Operating Area
• Gain Specified to IC = 1.0 Amp
• Complement to NPN 2N4921, 2N4922, 2N4923 and MJE4921,
    MJE4922, MJE4923
• Choice of Packages - 2N4918 thru 2N4920, 30 Watts, Case 77
    MJE4918 thru MJE4920, 40 Watts, Case 199