The Kensington K38036US provides up to 3 hours of extended talk time on your mobile phone and includes a mini USB charging cable for use with a BlackBerry Smartphone or Motorola mobile phone. This pocket booster also comes with two rechargeable AAA batteries for powering wireless mice and other devices. To recharge the batteries, just insert them inside the unit and plug it into your computer’s USB port!  You can buy two boosters for one shipping charge.