Can you connect more than 1 LED up together and link them ?

Yes you can. You will need a video card with a dual output to connect two LED Duos to the machine. You would then plug the two USB cables in and you would have touch on both units. If you have a 4 point touch model, you would have a maximum across both screens of 4 points – eg Screen 1 3 points and Screen 2 1 point, or just screen 2 with 4 points etc