Microair M760 Transceiver.

"Input Voltage 10 - 16 Volts Warning damage will occur above 16
Volts"

"The operator should remember that the minimum operating voltage is 10
volts. This is the loaded voltage (ie the voltage when the radio is
transmitting). For battery operators, check the battery voltage level,
then press the PTT briefly to note the voltage drop. If the voltage
dips by more than 0.5 volts, change the battery before flying."

I enjoy my active imagination but I can also read a spec sheet.