Features: 1.Digital Display: Simply immerse the PH meter electrode in the solution to be measured and the reading is quickly displayed on the large LCD screen. Multi parameter display at the same time, mobile APP control backlight display. 2.High Sensitivity Probe: Bluetooth water quality detection pen with high sensitivity glass probe can obtain full measurement range from 0?14pH with 0.01 PH resolution. 3.5 Point Calibration Method: Water quality testing pen is 5 point calibration method and equipped with calibration powder (Asian standard: PH 4.00, PH 6.86, PH 9.18, EU standard: PH 7.00, PH 10.01). 4.Professional Testing: PH meter with Bluetooth, professional measurement of PH, TDS (ppm), EC (conductivity), ORP, SG, salinity (ppt) and temperature. It can be used as a classic tester even if it is not connected to a smartphone. 5.Data Saving: Water quality tester's Bluetooth data transmission is accurate in real time and the measured values are visible at a glance, allowing you to easily save, manage and share test data without worrying about data loss. 6.Customizable Parameters: Water quality tester has fully customizable parameter settings. the app allows you to set upper and lower PH limits. When the value you set is out of the test range, the app interface will display the red value exceptionally. 7.Wide Application: Bluetooth water quality detection pen is widely used in drinking water, sewage treatment, water purification, fish tank, aquaculture, swimming pool, hydroponics, medical, etc. specification:Item Type: Water Quality Testing Pen Material: ABS Scope of Application: For swimming pools and spas, hydroponics, aquariums, aquaculture, etc. Built in Battery: LR44 x 3 450mAh Bluetooth: 5.2 Accuracy: 0.05PH Working Temperature: 0.1-60 () PackageList: 1 x Water Quality Testing Pen 5 x Calibration Powder 1 x Manual