- Bidirectional voltage detection from 3 to 90 V DC with a voltage tester pen design. Detects voltage in both directions and identifies polarity with an onboard LED: red for positive and green for negative. The alligator clip can attach to either positive or ground, making it easy to determine polarity in automotive circuits. - Durable and flexible construction. Built with high-quality copper and a shatter-resistant ABS shell for a sturdy yet flexible tool that can test in hard-to-reach areas without damage. - Clear digital display. A bright digital LCD provides easy-to-read voltage values at a glance and offers instant polarity and continuity indications with high visibility in low-light conditions. - Accurate and reliable readings. Engineered with precision electronics to deliver fast, trustworthy measurements. Functions include voltage testing, fuse testing, and car battery testing to help locate circuit issues with confidence. - Practical applications and compatibility. Designed for automotive circuits and general DC testing within 3-90 V, offering reliable performance for diagnosing electrical problems in vehicles and other DC systems. - Use scenarios: - Automotive electrical diagnostics: verify battery health, check wiring polarity, and test fuses in engine bays. - Motorcycle and marine applications: quickly assess DC supply polarity and circuit continuity in tight spaces. - DIY electronics and vehicle maintenance: confirm proper power rail polarity and test circuits in dashboards, fuse boxes, and wiring harnesses.