eD1: PC Interface Cable.
Connect this cable to a PC and download free system upgrades for your eTrex and eMap from Garmin.com. You can also save or load waypoints, routes, and maps.
Features ePlug, a custom 9-pin D connector, and very flexible cable.
You can also supply power via pin 8. Optionally connect a P3M6F power inserting cable to supply both power and data to your Garmin. (The two cables together we call the eMax. It's a Combo power data cable team!)
There is a moulded on ferrite bead to address EMI radio interference, a 4 conductor cable with all 4 wires connected to all 4 ePlug pins (with power connected to pin #8 on the DB9 connector).