NEC NP1200 User Manual page 96

Install the new lens
1. Insert the lens with the yellow protrusion on top.
2. Rotate the lens clockwise.
Rotate the lens until you feel it click into place.
Using the anti-theft screw to prevent theft of the lens
Tighten the supplied anti-theft screw on the front bottom.
Hole of anti-theft screw for lens unit
85
7. Using Optional Lenses
Yellow
Protrusion