1Pen Style Brake Fluid Tester: The brake fluid tester pen can detect the condition of DOT4 brake fluids and most synthetic brake fluids with fast and efficient testing process. 2Immediate Test Result Display: The tester adopts diodes to immediately display results in colors, green for 3%, indicating the need for fluid replacement. 3Portable and Compact Design: Well structured case fits comfortably in hand, making it convenient to carry while traveling without taking up much space. 4Wide Applicable: The brake fluid test strips can check the condition of DOT4 brake fluids as well as most synthetic brake fluids, widely applicable for private workshops, repair shops and car dealerships. 5Universal Compatibility: The automotive brake fluid tester is suitable for most vehicles and could test DOT4 brake fluid accurately and efficiently. 1 xBrakeFluidTesterPen