The Autel PowerScan PS100 is a versatile automotive circuit tester designed for diagnosing electrical system issues in vehicles. It features a 20ft extendable cable for easy access and a built-in flashlight for working in low-light conditions. This tool can test positive, negative, and open circuits, check for continuity, and diagnose circuit failures. It offers four operational modes: DC voltage, AC voltage, resistance, and tone on/off, making it user-friendly for technicians. The built-in circuit breaker ensures safety during use, protecting the device from overloads.