This Li-Po battery is for the E-Flite Blade MCX and MSR helicopters.
I have purchased a number of these batteries and they have all worked very well.
Each battery will give 8 minutes usage approximately, could be more, could be less, it really depends on your style of flying.
These are the manufacturers batteries, and not a copy and seem to be of a pretty good quality.
If you have either a Blade MCX or MSR and want more flying time, then this will be the answer.