Bayer HealthCare RapidPoint 400 Series Service Manual page 50

The AutomaticQC cartridge is disengaged from the system through a
software procedure that causes the stepper motor to move the sliding
metal latch plate and release the standoffs. If power is lost, the
AutomaticQC cartridge can also be disengaged from the system by
moving a release tab located beneath the stepper motor.
AutomaticQC Interface
1 Latch assembly
2 Locating holes (4)
3 Actuator
4 IDEE Pins
50 Rev. C