ANCEL GD100 Combustible Gas Leak Detector Pen with Buzzer Alarm Car Pipe Leak Diagnostic Tool Emissions Gas Analyzers Tools. MODEL: GD100. Audible:Variable Tone Frequency Buzzer. SENSOR FAILURE In case LED(Green/Red) turns to red color with continuous buzzer and LED(Yellow, Orange, Red )are all off during use, the sensor of detector fails is no longer working properly.
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