* BlueTrack Technology - Works on virtually any surface including granite countertops, carpets and wood tables
* Nano Transceiver - Leave plugged in when you're on the go, or stow in mouse
* 4-way scrolling and 4 customisable buttons - Additional advanced features with included software
* Up to 10 months' battery life - Battery status indicator lets you know when your battery is running low
* 3-year limited hardware warranty
I just got one of these for my wife - it's a very good mouse. It even works on her knee or the settee, so is ideal for use with a notebook.
There are other colours available, but they are more expensive.
This generally seems to retail around £25 - so this is a pretty good saving.