Diagnostic Motor Rotation Indicator: Professional AC detector designed for testing energized solenoid valves, motors, and certain circulation pumps - when placed near a magnetic field, the internal disc rotates to indicate motor operation direction, helping you quickly determine if equipment is functioning properly even in noisy industrial environments. Visible Operation Confirmation: Small rotating disc inside the transparent tester housing spins when detecting active magnetic fields - you can both see and feel the movement, making pump and motor diagnostics simple and immediate without relying on sound or touch in high-noise workshop settings with multiple machines running. Lasting Construction Materials: Tester housing crafted from crack-resistant ABS plastic protects internal components from workshop damage, while the test disc utilizes a sensitive magnet for accurate field detection - robust build quality insures reliable performance across repeated diagnostic tasks in demanding commercial and industrial applications. Portable Keychain Design: Compact lightweight construction at small dimensions allows easy storage in tool bags or attachment to keychains - always have this circulation pump AC detector within reach for quick troubleshooting of solenoid valve systems, motor operations, and pump functionality checks throughout your workday. Multi-Color Options Available: Package includes 1 solenoid valve rotation tester in your choice of green, pink, or brown housing - Note: Slight size variations may occur due to manual measurement, and colors may appear differently based on screen display settings; refer to product images for accurate representation.