For me there is no doubt the Thinkpad Bluetooth keyboard is the one https://support.lenovo.com/us/en/solutions/pd026744 https://support.lenovo.com/us/en/solutio

For me there is no doubt the Thinkpad Bluetooth keyboard is the one https://support.lenovo.com/us/en/solutions/pd026744 https://support.lenovo.com/us/en/solutions/pd026744 they are difficult to purchase from some reason, I am not totally sure there still manufactured. I just manged to order 2 in the UK 150 pounds each