If sometimes you are absent-minded like me, this continuity tester will forgive you by protecting itself and the circuits under test.

Withstands sustained voltages up to 35V.
Safe open circuit voltage: 100mV.
Short-circuit current: 5mA.
Adjustable threshold from 1 up to 20 ohms.
Lead wires resistance compensation.
LED conduction indicator supplements beep.
Powered from 2xAAA cells with battery test.
Reverse battery protection.
Low open circuit consumption: 0.5mA.