Paranormal phenomena causing the air to ionize? This hand-held ion counter possesses the same sensitivity (down to 10 ions/cm²) as meters costing far more. Fully electrostatically shielded, with a fan throughput of 200 cm³/sec, it can make accurate readings even in adverse conditions. Measures positive and negative ions separately. Made in USA . 9-volt battery included. • Setting Time: 10 sec • Noise level: 10 ions/cm³ • Accuracy: ±25% for fast ions • Ion selectivity (crosstalk): 20x • Range: 10 - 1,999,000 ions/cm³