GP-1 GPS Unit...Geotags can be added to your images so you can record latitude longitude altitude and time information. Geotag (image positioning information of pictures such as latitude longitude [Geodetic System WGS84]) can be added to the image. Correlation between pictures and maps is supported by GPS function in conjunction with ViewNX version 1.2 software (no-charge download) and my Picturetown. Acquired data: Latitude longitude altitude time information; Time required for satellite acquisition: Approx. 45 sec. (cold start) approx. 5 sec. (hot start); Power source: Supplied from camera body; Receiving indicators: Red blinking (GPS data not recorded) Green blinking (GPS data recorded utilizing three satellites) Green solid (Four or more satellites detected GPS data are more accurate). Compatible models:D90 (via accessory terminal cable GP1-CA90) D3 D300 D700 D2Xs and D200 (via 10-pin remote terminal cable GP1-CA10). Some models may require an update to the latest version of firmware. Attachment: Attaches to camera?s accessory shoe or a camera strap via strap adapter GP1-CL1. Includes GP1-CA90 for connection to the D90 GP1-CA10 for connection to the 10-pin remote terminal of supported cameras Strap adapter GP1-CL1.