USB Charging. MicroScrollTM. 800dpi.All New From The Ground UpWhile manufacturing The Mouse BT we had several ideas for improvements that could not be readily incorporated into the existing design. So, we decided to make a blank-sheet effort and here is the result. Our all-new Bluetooth transceiver module is state of the art, and incorporates the range increases and power conservation benefits of the latest BT v1.2 standard. Since the number one customer request from our earlier product was to move to rechargeable batteries, we have created a mini-USB charging cradle that takes up little deskspace, but makes charging the included AAA NiMH batteries quick and easy.Our MicroScrollTM Scroll WheelApple"s use of a miniature scroll ball on their Mighty Mouse product exposed many users to a new and seemingly contradictory concept: a tiny scrolling device "feels" more precise in usage than a larger one. However, many of these same users have learned that a sealed, embedded mini-trackball is not the perfect implementation of this idea. Our MicroScrollTM miniature scrollwheel delivers the precision of an ultra-small scrolling device, but without the frustrations of a tiny trackball. It uses a 10mm diameter clickable, notchless design that provides smoothly gliding, highly precise operation, and a silky smooth feel.The Mouse BT II is a Bluetooth wireless 2-button mouse with 10mm miniature clickable scroll wheel. It is plug-and-play compatible with both Mac OS X and Windows XP systems that support Bluetooth. It uses (2) included AAA NiMH rechargeable (user replaceable) batteries and an included mini-USB desktop charging cradle that plugs into a USB port on your computer.