GPS Receiver for Nikon D3100 Cameras | Hackaday.io
Micnova GPS-N Plus GPS Receiver for Nikon Cameras | eBay
Micnova ELELAB07GZPW193 GPS-N Plus High-Precision Camera GPS Receiver Navigation Geotagging for Nikon D3100, D3200, D3300, D5000, D5100, D5200, D5300, D