1.360°Full Protection Desig<br /> iPhone 7 / 8 battery case offering your iPhone great protection and secure grip featured with 1.2mm raised front lips to protect your iPhone 7 / 8 from scratches， bumps， drops and more <br />2.Advance Lightning Sync <br />When sync data， no need to remove the battery case. Marsno charging case have data transmission function and the speed is the same with iphone own interface. <br />3.Extend Battery Life <br />This case more than doubles your iPhones battery life without doubling its size. Use original lightning cable to charge your iPhone 8 at first， <br />then transfer to charge the battery case automatically <br />4.Lightweight  Stylish Design <br />Designed to match slim profile of the iPhone for a natural look and feel，the elegant black profile of the case makes it the perfect matching accessory in almost any situation <br />5.How to Charge your iPhone <br />Please make sure the battery case is well installed， check the power remain for the first use， <br />Press on-off buttom 3 seconds to charge/stop， 1 second to show the remaining power. <br /><br />Capacity: <br />4000mAh for iphone 6 Plus / iphone 7 Plus / iphone 8 Plus<br />3000mAh for iphone 6 / iphone 7/ iphone 7<br />3200mAh for iphone X<br /><br />IMPORTANT NOTE: <br />Not compatible with Apple stock， wireless charging or traditional 3.5mm headphones. ONLY compatible with Apple Airpod Bluetooth headphones or any other wirelessly connected headphone accessories. <br />Specifically designed for iPhone 8<br /><br />Box Content :<br />1 x iPhone  Battery Case <br />1 x User Manual