Epson Expression 1680 - Manual (Page 71)

4-2 Options
Removing the shipping screw
A shipping screw is installed on the Transparency Unit to prevent
damage during shipping. Be sure to use the following procedure
to remove this screw before attempting to use the unit.
1. Turn over the Transparency Unit so its glass side is facing up.
2. Remove the shipping screw as shown below.
3. Screw the shipping screw into the storage hole as shown.