Features Measurement Plan: This air ion tester is designed for testing high concentrations of negative or positive air ions. The tester's reading is related to the air ion concentration, but not exactly its quantity. Function: This instrument can be used to judge whether the polarity of the negative ions generated by the negative air ion generator or air purifier is correct, and to estimate the ion concentration. Easy to Carry: This air ion tester comes with a wrist strap, simple and compact design, easy to carry, very easy to hang as a bracelet. With it you can tell if the air ionizer or air purifier is working well. Measuring Range: 10000 --- 19,990,000 (ion/cc) Resolution: 10000 (ion/cc) It is suitable for the measurement of various negative ion generators, air purifiers, air conditioners, and high-concentration ion sources. Note: Please carefully confirm the use precautions in the product pictures. We attach great importance to the customer's purchasing experience. We hope you can have a pleasant shopping experience. Thank you! Descriptions: This instrument is a qualitative product, rather than quantitative products, because of the accuracy, only suitable for testing values of negative ion air purifiers and negative ion generator, and there are certain floating customers, if you mind, choose others please, thanks. Specification: Power supply: 2 x 1.5V LR44 button battery(built-in) LCD Display: Maximum reading of 1999 Test range is between 1x10000 to 1999x10000 ions/cc Resolution:1x10000 ions/cc Dimensions: 8 x 3 x 1.3cm/3.15 x 1.18 x 0.51inch Weight: 89g Note: 1. This instrument is a-high impedance measuring meter, it must pay attention to moisture when using and collecting, if moisture appeared then testing is unstable, reading disorder and other problems, then the available hair dryer or drying in the sun. 2. When the battery runs low battery symbol appears, it should open the back cover to replace the battery with the specifications and attention battery polarity. 3. If you need to get a more accurate ion content or measured ion content in the environment less than 10,000 (ions / cc) of the following, choose other anion detector please. Package Included: 1x Air Ion Tester 1 x Blue wrist strap Note: The product has 2 built-in button batteries. In addition, four external button batteries are needed, but the four external batteries are not included. Package List