Feature: 1. Quick and Easy Testing: With the car aircon oil checker, testing your car's air conditioning oil level becomes quick and hassle-free. Simply start your vehicle, set the air conditioning to maximum airflow, and press the checker onto the refill port 2-3 times. Obtain instant measurement results for necessary actions. 2. Compatible with R134A and R12 Systems: This auto air conditioning system oil tester is designed for use with R134A system oil and R12 detection cotton. For accurate results, it is important to sufficient refrigerant in the vehicle before conducting the test, ensuring no shortage of refrigerant during the detection process. 3. Convenient Testing Conditions: To perform the test for this A/C oil tester, open the car doors or lower all four , set the airflow to maximum, and adjust the temperature to a lower setting. Let the vehicle run for a few minutes, and you're ready to conduct the oil level check, ensuring optimal testing conditions. 4. Simple and Efficient Operation: Align the refrigeration oil testing instrument with the low-pressure port, press it firmly, and release immediately without any prolonged pause. Repeat this process twice, providing a rapid and efficient way to measure the oil level status of your car's air conditioning system. 5. Optimal Performance: By regularly checking your car's air conditioning oil level, you can maintain the optimal performance of the system. Proper oil levels contribute to effective cooling, preventing potential issues and extending the lifespan of your car's air conditioning components. Tips: The product may be updated constantly, The Actual Product May Have Slight Differences Or Color Differences the color and appearance may be changed, please don't mind. And take a conside Different batches, different angles and lighting, there are slight differences between the product and the actual product, which does not affect normal use. Material: plastic + cotton Color: as shown Package Contents: 10 x Car Aircon Oil Checker Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.