Review of Linux Compatibility
The Lenovo N5901A Mini Keyboard communicates via 2,4GHz with the included receiver (an not via Bluetooth), which is connected to the PC. The keyboard has the USB ID 17ef:6014:
Bus 001 Device 004: ID 17ef:6014 Lenovo Mini Wireless Keyboard N5901
and is fully supported by Linux (at least since Ubuntu 10.04). The N5901A is automatically recognized is plugged in and gets nitialized by the kernel.
The succesor model N5902 additionally has a illumination of the keyboard in order the ease its usage in darkness.