From the front, you can see there is a square bulge on the left-hand side. This is the wireless feature. When a person thinks "wireless", they often think of radio signals. And why not--everything that is considered to be "wireless" generally has a radio signal associated with it. Not with the SB-80DX. The SB-80DX has, what I term, Optical Wireless Capability (OWC). This means the flash is tripped via a light source. When the SB-80DX "sees" a compatible lightsource, it trips the flash. It is too bad the SB-80DX is not a true wireless flash (like the PocketWizard MultiMAX), because it could probably be the only flash a person would ever use. Simply buy 3 or so SB-80DXs, and you would be set for almost any portable event. But, as any digital photographer knows, life is just not that easy, and the major camera manufacturers are not completely aware of what photographers need. With Nikon's newer SB-800DX Speedlight, you can now operate the flash like a Multimax, because it uses frequencies to transmit information to the speedlight. It is not clear how much of this versatility can be used on a D100 or earlier D-series DSLR. The D2h (and the yet-to-be announced D2x) is officially the only DSLR so far to be fully compatible with the SB-800's features.