BN-180 GNSS GLONASS Dual GPS Module Antenna for Arduino Flight Control Aircraft UART TTL Level Small Size 9600bps

Probably the best in its class, acquire sat quickly, doesn't get hot, prefect for RTH during failsafe.

Works ok but you have to do a "warm up" before most flights or you'll never get a sat lock. Other than that it works well I can acquire around 15 satellites in certain areas and only 5-8 in other areas. Did not require any flashing for use with betaflight