Intermec PB42 Guide D'installation page 5

3 Attach the vehicle cradle to the RAM vehicle base by placing
the mounting arm over the two bases and then tightening the
mounting arm.
RAM cradle
base
4 Insert the PB42 into the vehicle cradle making sure that the
PB42 makes good contact with the pins on the vehicle cradle.
5 Push in and turn the knob on the vehicle cradle to secure the
PB42.
Vehicle
cradle
Mounting arm
PB42
RAM vehicle
base
Vehicle
cradle
Push in knob
and turn clockwise
5