Unifier usb - it stores which devices are paired and (at least for me) pairing is done with the computer. Plug in the unifier to a computer and pair using the unifying software that comes with the keyboard and mouse. I can't recall if out of the box unifier and keyboard/mouse are paired. When I changed keyboards, I retained the previous unifier and stored the new with the old keyboard.
Unplug the unifier from the computer and plug into your Acer. It is recognized as a physical keyboard and you are off and typing, mousing, etc.
Just sharing for those who may have struggled like me I am using the K400 but also tested with a K330.To my knowledge and reading other forums many LT keyboards and mice should work.