Yes, Gionee M7 Power is a true 4G VoLTE mobile phone.
Thanks to fast charging support, it takes about 2 hours time to fully charge Gionee M7 Power's huge 5000 mAh battery - from zero to 100%.
Yes, Gionee M7 Power does have the hybrid sim slots. You can either use 2 Sim cards or 1 sim card and 1 memory card.
Yes, Gionee M7 Power does have the fast charging support.