The Fenix E-SPARK Keychain Flashlight not only a great everyday carry flashlight, but it also operates as a small backup power bank. The power bank is perfect for those moments when you just need just a little extra power before your next opportunity to charge your device. It can charge about 10% of your phone's battery which is perfect in an emergency situation. Use the three brightness levels to light your path and the red light for up close tasks where you need to preserve your night vision. And the tail cap that protects the charging port can also be used as a flashlight diffuser. Small, slim, and stylish, this flashlight/power bank will certainly become your favorite keychain companion.