Nikon D300 User Manual page 497

Figure 5-31. D300S with Nikon GP-1 GPS and GP1-CA10
cable
In Figure 5-32
included data cable, and the Nikon MC-35 cable (on the left).
This type of GPS outfit works well, but there's an awful lot of
cabling hanging around. The MC-35 cable plugs into the
camera, the GPS unit's data cable plugs into the MC-35, and
the GPS unit plugs into the data cable.
Newer handheld GPS units use USB cables, and even though
the D300(S) has a USB port, it is not designed to work with
aftermarket GPS units. If you decide to use an aftermarket
GPS, just make sure you can get a data cable for it with a
D-sub 9-pin connector to plug into the Nikon MC-35 cable.
Both GPS unit types allow you to use a cable release to fire
the shutter.
we see the Garmin eTrex Legend GPS,
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