Which is the real SterlingTek
Be careful about which charger you use to recharge your batteries. My Canon charger for my 5D batteries will fully recharge a Canon battery, but only partially recharges a SterlingTek battery - even though it shows the battery is fully recharged. Canon batteries have a chip in them which communicates with the recharger.
The SterlingTek recharger, however, recharges both brands of battery equally well, is smaller than the Canon version, is a fraction of the price of the Canon version, and even has a built-in flashlight.
If you buy StirlingTek batteries, buy SterlingTek rechargers also, and you should be happy.