Clear digital display for fast, accurate readings Bright LED screen makes voltage easy to read in any lighting condition. Reliable 1 V resolution provides the precision needed for quick diagnostics. Fast detection across common vehicle electrical systems Designed to swiftly test battery voltage and electrical circuits in 3 V to 48 V systems. Supports alternator testing for cars, trucks, and boats, helping you identify charging problems quickly. Durable, safe construction Made from premium ABS material for a shatterproof, impact-resistant body. Ergonomic handle improves grip and comfort during repeated use, reducing hand fatigue while troubleshooting. Practical, versatile tool for automotive electrical work Ideal for checking headlights, taillights, turn signals, and fuse connections. Compact and easy to use at the roadside, in the garage, or on a boat. How this tool helps you Find the problem faster: a quick voltage readout tells you whether a battery, connection, or alternator is at fault so you can take the right next step. Reduce guesswork: consistent 1 V resolution prevents misdiagnosis and unnecessary part replacement. Work safely and comfortably: durable ABS construction and an ergonomic handle make inspections less stressful and more reliable. Use scenarios Dead-start diagnosis: measure battery voltage before and after a jump-start to determine if the battery holds charge or needs replacement. Alternator check: read voltage with the engine idling and at higher RPM to confirm the alternator is charging within the expected range. Lighting and fuse troubleshooting: quickly test headlight, taillight, turn signal circuits and fuses to locate shorts, open circuits, or poor connections. Specifications and compatibility Voltage range: 3 V to 48 V systems Display: bright LED with 1 V resolution Construction: premium ABS, shatterproof Applications: battery and alternator testing, lighting circuits, fuses — suitable for cars, trucks, and boats A compact, reliable electrical test pen that simplifies automotive diagnostics, speeds up troubleshooting, and withstands daily use.