Nikon D7200 body - Manual (Page 129)

129 Menu Guide
Record the focal length and maximum aperture of non-CPU
lenses, allowing them to be used with functions normally
reserved for CPU lenses.
Non-CPU Lens Data
G button
➜ B setup menu
Option Description
Lens number Choose a number to identify the lens.
Focal length (mm) Enter the focal length.
Maximum aperture Enter the maximum aperture.