PRECISE READOUTS & CLEAR DIGITAL DISPLAYBright LED display shows highly clear readings in any lighting condition, 0.1V resolution gives you reliable indication and shows you the voltage number easily & quickly. Bidirectional light emitting diode on the circuit board for easy battery load testing, red light indicates positive polarity, green light indicates negative polarity. QUICK DETECTION & EXTENSIVE USEauto circuit tester helps you to quickly test car battery voltage and diagnoses issues in 3V-48V systems, including alternator tester functionality of car/truck/SUV/boat charging systems. Also to inspect circuit tester integrity of headlights, taillights, turn signal circuits, faulty sockets, fuse connections and more. SHARP PROBE & ANTI-LOST PROTECTIVE SLEEVESharp stainless steel probe for piercing insulation with ease, also for hard to reach tight areas. Integrated anti-lost protective sleeve to secure the probe during storage and safeguarding against damage, making sure no stab and