iPhone6/6s Plus Battery Case 8000mAh Power Bank External Backup Battery Charger Cover For iPhone6/6s Plus 5.5" (Black) Highly capacity 8000mAh iPhone6/6s Plus 5.5 Inch Battery Charger Cases Working Principle: pass/transport power from case itself to mobile phones One switch on/off button for easy operation, LED lights to indicate charge status,Built-in kick stand for Video Watching More convenient PC Material:high desity,high hardness,high purity,Environmental, non - poison, non - flammable, endurable to aging, climate, chemicals. Side extra USB port can help do other emergency charging for other USB devices when needed