Solmeta GMAX-GD Photo/Video GPS BDS Dual-positioning Geotagger & Bluetooth Shutter Release for Nikon D5, D810, D800, D4, D3, D700, D300S...with 4GB Flash,1900mAh Li-ion, Altimeter, eCompass, LCD... Embeds location, time, shooting direction into video or image EXIF for Nikon D5, D4s, D4, D3-series, D810A, D810, D800, D800E, D500, D700, D300S, D300, D2x, D2xs, D2Hs, D200 Dual-positioning systems: GPS and BeiDou (BDS) provide 20% more location accuracy than GPS alone, faster signal acquisition Can act as a stand-alone "Trace Logger" while sailing, hiking, flying, skiing, traveling, etc. 4GB Course Logger plus altitude & speed data, runs 18hrs without camera battery drain Measures Barometric or GPS/BDS altitude, user can choose their preferred altitude data base on actual environment Bluetooth technology enables the iPhone itself used as a remote triggering device for the user's DSLR camera. 2 years Mfg. Warranty!