Check the lock ring: This tool can be used to test the lock ring functionality. Antenna tester: Designed for car lock detection circuits and car key lock chip antenna testing. Small tip: If the indicator light turns on but the car cannot start, it indicates a potential issue with the chip. Useful detection tool: An essential device for automatic lock system diagnostics. How to use: Test the automatic lock system. If the light illuminates, the lock ring is functioning properly. If the light does not turn on, there may be an issue with the lock ring. If the light turns on but the car still fails to start, the problem may lie with the chip. Inductive signal detection card: Capable of identifying lock ring issues. Durable in construction and user-friendly. Note: Installation guide is not included. Professional installation is strongly recommended. Please verify the product specifications to ensure compatibility before use. The image shown is a high-resolution ring. Due to production variations across batches, slight differences in color or appearance may occur. These variations do not affect performance. Color: Red Material: Plastic Package Contents: 5 x ECU Induction Signal Detection Card Package includes only the items listed above; other accessories are not included. Note: Lighting conditions and display settings may cause slight color variations between the product image and the actual item. Measurement error allowance is +/- 1-3 cm.