Auto Car Mini Electronic Brake Fluid Liquid Tester Test pen - Black ( 1 x AAA)
Model: SD-66 - Color: Black - PVC housing material - Shows the condition of brake fluid with a colored response - LED red: Water content in brake fluid H20>3% change brake fluid - LED green: H2.0 - LED yellow: H20=1.5%~3% brake fluid OK check again after 6 month - LED red flashing: Change battery - Powered by 1 x AAA battery