DIYmall 6M GPS Module with EEPROM for MWC/AeroQuad with Antenna for Arduino Flight Control Aircraft Document link: https://engineersportal.com/blog/2018/5/9/comparing-iphone-gps-against-neo-6m-gy-gps6m-gps-module-with-arduino Youtube link: https://www.youtube.com/watch?v=VziqwqLaGso LED signal indicator,With data backup battery EEPROM power down to save the configuration parameters data One year warranty,we offer free sample to anyone who can make projects,please contact.Thanks.