The iPower Reminder* provides your first line of defense against loss or theft of your iPhone 4/4S. A loud 95 dB alarm on the iReminder Tracker alerts you, even in noisy environments, whenever the iPower Battery Pack is separated from the iReminder Tracker by more than the user selected distance of 16' to 32' (see specifications). The iReminder Tracker and the iReminder Battery Pack both have a "Find Me" button that helps either device locate the other within a 100' radius. The iReminder Battery Pack contains a lightweight ultra-thin 1,900 mAh Lithium Polymer Rechargeable Battery that can give you up to double the talk time of the iPhone 4/4S battery alone. *iPhone 4/4S is not included. SPECTIFICATIONS: Model Name --- iPower Reminder 608i ; Function --- Reminder alert, Rechargeable & FindMe ; FindMe Range --- 0~100 feet (0~30m) Alarm Distance ---Near : 16'±9'(5m±3m) Far : 32'±9' (10m±3m); Devices --- iReminder (Tracker) and iPower (Battery pack); Battery Types: CR2032x1 for iRemider / Lithium Polymer rechargeable battery Capacity: 1900mAh for iPower (Battery Pack); Battery Life Time with Standby ---Up to 50 days (based on 8 hours standby / day) for iReminder. Up to 300 hours for iPower; Beep Sound (at 10cm/3.9inch) --- 95 db; Weight --- 0.3 oz.(9.5g) for iReminder; 2.64 oz.(75g) for iPower battery pack. Dimension (L/W/H): iReminder --- 2.42" x 1.42" x 0.46" 61.5x36x11.6mm; iPower Pack --- 4.96" x 2.48" x 0.62" 126.5x63.3x16.7mm