William Wallace Eachine goggles. Works perfectly fine.

William Wallace This will vary greatly based on your particular setup and any answer we give will be an extremely rough estimate. Antenna choice as well as antenna style will play a significant role in the function of this device and its range. Quality antennas and directional receiver antenna with line of sight (clear view from the TX to the RX with nothing in between) can go an extremely long distance on very low power so your "mileage may vary". At 25mW I would not expect tremendous range from this unit without the use of quality antennas used correctly but it is very hard for me to give you a precise number at all. If you would like long range I would go with a stronger transmit power (remember to check laws etc blah blah).