The Acustrip Diagnostic Detective helps technicians monitor brake fluids for early signs of corrosion. The Acustrip brake technology provides results in under a minute to determine if potentially harmful, unsafe or damaging conditions exist. To use, dip the test strip into brake fluid and read at 30 seconds. Acustrip test strip works in both DOT3.0, 4.0 and 5.1 brake fluids. Diagnostic Detective is available in bottles of 50 (No. 61050) and in a dispenser of 100 (No. 61000).