Forget the silly RRP shown on Amazon, but this mouse has been a lot more expensive than this. It is a good quality wireless mouse designed for laptops.
The dongle fits into the USB port of the laptop when in use, and fits snugly into the bottom of the mouse for storage. Doing the latter also switches off the power so saving batteries.
Prices for computer equipment on Amazon seems to change almost daily, so the price may have changed by the time you read this!