A:connects only with one laptop. to connect with another laptop, you have to reset and reconnect
So it works with one laptop only. I hope I answered your question.
Q:Does it have a smart sleep , or auto off feature when idle ?
A:This feature is written in the product description. There is no LED to show power on/off. So there is no apparent proof.But as the battery life is claimed as 18 months,we can assume it's auto-off.
Q:Does it provides the dongle also?
and can connect it connect to multiple devices?
A:No, the mouse doesn't have dongle. And it cannot be connected to multiple devices with a switch. You need to manually connect to other devices by long pressing the button.