Features:It is specially designed for Samsung Galaxy S3.Ultrathin design, compact and light weight without increasing additional weight of the S3.Adding wireless charging feature by piggybacking it on the battery of S3, it works well with any Qi-enabled charger.Easy to use.The receiver can be attached to the the battery all the time, and it would not interrupt the normal use of the S3.How to use it : Step 1: Open the back cover of the Samsung Galaxy S3;Step 2: Stick the receiver card to the mobile phone's battery and the two protuberant touch points must touch the two recesses next to the battery;Step 3: Close the back cover;Step 4: Place the mobile phone onto the Qi wireless charging pad (not included).Specifications:Color: WhiteInput power: WPC5WOutput: 1000mACharging current: DC5V/500mA (Max)Charging time: 5 ± 0.5 hrsReaction temperature: -10 ～ 40℃Working heat up range: ≤20℃ (ambient temperature ≤25℃)Working ambient humidity: ≤80%Working life: Charge & discharge ＞ 4000 timesSize: Approx. 61.5 * 49.3 * 1mm / 2.4 * 1.9 * 0.04inWeight: 5g / 0.17ozPackage list:1 * Qi Wireless Charging Receiver for S3