The GN-8620 has a TTFF time at Hot start of less then 1s, Warm start of 30s, and Cold start of 33s, and can operate between -40°C to 85°C, while only consuming 68mA of power in Acquisition mode. The GN-8720 has a TTFF time at Hot start of less then 1s, Warm start of 30s, and Cold start of 33s, and can operate between -40°C to 85°C, while only consuming 72mA of power in Acquisition mode.