I just received my Zitay 7.2V External Battery and LP-E6 Canon Dummy Battery for my Canon DSLR 5D MK II. The battery is larger than I imagined and came fully charged. I haven't had a chance to test it for a long shoot, so I can't speak to how long it will last, but based on the specs it should last a whole night of astrophotography. The Dummy battery fits perfectly in my camera and I can even close the battery door. I would recommend this to anyone who needs a long-lasting battery for drawn out shooting times.