Interlogix TruVision IP Megapixel PTZ Installation Manual - Manual (Page 12)

12 Installation Guide
6. Install the housing onto the mounting base. Line up the
direction of the arrow on the housing with the spring end
of the mounting base. Push the housing upwards (A)
and then forwards (B) in the direction of the arrow.
When the housing is placed in position, the spring will
automatically snap into the lock clip firmly. Refer to the
figures below.
Line up
B. Push forward
A. Push upward
Lock clip
7. Insert the PTZ module into the housing: