FEATURES Compatible working with all kinds of USB-powered devices. High quality guarantee -A grade Samsung battery cell inside. Tube appearance, slim and light-weight design, easy to carry. Complete protection: Over current , Over discharge , Over charge , Short circuit protection TECH SPECS Model: Walk 2200 WS/WP Battery Capacity: 2200 mAh Input Voltage: 5V Input Current: 0.5A Output Voltage: 5V Output Rating: 1A Dimensions (LxWxH): 110 x 28.9 x 28.2 mm Weight: 75g Operation Temp: 0~40C / 32F~104F Protection: OCP/ODP/OCP/SCP