For all CFC, HCFC and HFC Refrigerants One-Hand Operation -- The 16" gooseneck probe holds its position so you can operate the detector with one hand. Audible and Visual Leak Indicators Threshold Balancing Control -- Gives you infinite control for eliminating background contamination so you can zero in on the leak site Volume Control Dependable Leak Detecting; The 16600 uses proven corona discharge technology to sense leaks. It works by creating a high voltage corona in the sensing tip. When this field is interrupted by refrigerant, the alarm is triggered. All corona discharge leak detectors are not the same, however -- the quality of key components is critical in providing an effective instrument. Sensing Tip; The materials, shape and finish of the sensor and surrounding shell are critical to the effectiveness and life ot the tip. The 16600 is built with a mirror finish and specially engineered tip for superior sensitivity and durability. The tip can be cleaned for even longer life. Specifications: Power Source: Four AA alkaline batteries (included) Battery Life: Approximately 25 hours Dimensions: 8-1/2" L x 3-1/4" W x 2" D (21.59 cm x 8.26 cm x 5 cm) Probe Length: 16 in. (40.6 cm) Weight: 1.14 lbs (.52 kg) with batteries