Phoenix Systems 8002-B Double-Ended Test Strip for Coolant + Brake Fluid (Determines When to Replace Coolant and Brake Fluid) The dual ended strip increases level of service, ensuring that every vehicle has both coolant and brake fluid tested Brake Strip provides a visual reference for brake fluid copper corrosion levels Coolant Strip effectively measures the pH level and glycol percent of engine coolant The double-ended strip provides easy to read visual proof for when you should or should Not change these vital fluids