IBM X4 manual

3.Secure the adjuster in the proper position. The position of the adjuster depends on the computer model and the type of battery installed. Refer to the label attached to your ThinkPad X4 Dock.

4.If you are using the ThinkPad X41 Tablet Series computer, align the left side of the computer with the guide on the left side of the X4 Dock; make sure that the docking connector on the bottom of your computer and that on the X4 Dock are aligned with each other.

1-6ThinkPad® X4 Dock User’s Guide