What a great wireless optical mouse, and at £10.95 via Amazon, you just cannot go wrong!
An absolute breeze to set up; insert the supplied AA battery into the mouse by pressing the button underneath to release the battery cover, then plug in the mini-receiver into the PC (XP in my case) USB port and it's ready for use!
The mouse is of a nice size and comfortable in the hand. No apparent problems with tracking, in fact it's very responsive. I've downloaded the free software from [...] and this allows a variety of functions to be set up, including change of function of the middle button (I've set up the middle button so that when clicked invokes a zoom function which is really useful), response speed can be adjusted, & the software also monitors the battery strength and can provide a low battery alert on the PC.
The dongle clips into the base of the mouse when not in use and in the process of clipping in or out switches the mouse off or on, respectively. Underneath in the recess where the dongle is stored are three buttons, the battery compartment lid release, a connect button, and the on/off switch. There's also a led on top which is green when first switch on and will flash red when the battery is low.
All in all, for the price, a cracking product from Logitech.