4-in-1 pH Meter, pH Tester, pH Tester, pH Meter with LCD Display, High-Precision Resolution 0.01, Pool pH Meter 【4 in 1】For checking water quality, whether it comes from a faucet, hot tub, homebrew, indoor soil, aquarium, hydroponics, or swimming pool. In addition, the pH meter pens are small, lightweight, and easy to carry when you go out. 【High Accuracy】The pH meters range from 0.00 to 14.00 (PH). 0.01 pH pH resolution, ±0.01 pH accuracy, blue backlit LCD display for reliable and fast readings. 【EASY TO CALIBRATE】The pH tester automatically calibrates at three points. No tools are needed; Simply remove the protective cap and immerse the pH meter electrode in the solution. Press "ON/OFF" to turn on the electronic pH meter, stir gently, and wait a few seconds for the reading to stabilize. 【EASY TO USE】 The pH tester features a self-calibration function that allows you to quickly obtain a reading. 【Widely Used】 A single calibration powder can be easily stored in a drawer, bag, or