Fits fine to X1 Carbon Touch

Edit [31.10.2013]:
Bluetooth pairing is now working properly yet. Apparently, the power management has the mouse off periodically to save energy. Therefore, upgrade to 5 star. Who uses the mouse on the X1 Solte therefore check whether the power management turns off Bluetooth devices to save energy. This function must be deactivated so that the mouse is working properly.

The mouse itself fits in design great for X1 - am very satisfied

The mouse has connectivity issues with the Lenovo X1 Carbon Touch (Windows 8 and 8.1.). Initial Bluetooth pair works fine, but after 2-3 hours or after waking from sleep is the connection path and can not be recovered even by switching on / off the mouse or renewed search. Must then remove the mouse from the Bluetooth device manager and re-connect again - quite annoying. Whether this is now on the mouse or on the X1 I have to investigate.