For viewing the documentation in a pdf you need to install Adobe Acrobat Reader. It can be download here:
TIP121
Plastic Medium-Power DARLINGTON NPN transistor designed for general–purpose amplifier and low–speed switching applications,(Uce=80V, Ic=5A, h>1000).
VCBO (IE = 0) 80V
VCEO (IB = 0) 80V
VEBO (IC = 0) 5 V
Collector Current 5 A
Collector Peak Current 8 A
Base Current 0.1 A
Total Dissipation at Tcase Ј 25oC 65 W
B>1000 @Vce=3V,Ic=3A