Build your own power module for the Fatshark goggles. Use a variable power regulator to regulate any connected lipo to feed the goggles (and fan) 2s power only. Having the module sit on the headband also relieves tension on the power port on the goggle. Attach a LED to show when the module is getting power. At quick glance you can tell if the power is being regulated because the LED will be less bright than at full unregulated power. Useful for pilots who like to fly with a big lipo in their pocket... or for providing a backup goggle power source - since you can connect your flight packs to power your goggle.