That is the remote unit for a qualcomm unit. it will read a new message to you while driving when the main unit blanks out while the tractor is moving. Depending on the programming you may be able to do more such as line by line directions as sent by dispatch. That unit is cheap and they seldom remove them as they cover a hole in the dash.
If I understand it correctly there are only 4 parts to that type of QC system. The main QC unit. The hand unit and this part plug into the main unit and the antenna. I would highly recommend not removing it unless you have something to cover that hole with. Trust me. I don't care how much attention you pay to the dash. A hole in the dash that size will cover the inside of the dash with dirt. Dirt and grime can lead to problems with other things in that dash. If you still have a QC just unplug it.