Accurate And Stable Results: Automatic Temperature Compensation and multi-point calibration adjust for temperature changes, so this pH pen gives consistent readings for confident water monitoring at home. Easy-To-Read Lcd Display: The illuminated screen shows pH values at a glance, even in dim light, making it simple to check water quality readings quickly during your daily testing routine. Data Hold For Easy Records: lock the value on screen, so you can note down or compare pH results without rushing, helping you keep track of water conditions over time. Compact And Travel-Friendly: This lightweight pH tester pen slips into a pocket or bag, letting you test tap water, pool water, and hot tub samples anywhere for easy routine upkeep. Simple One-Button Testing: Made for home, lab, classroom, or hobby use, this liquid solution tester checks hydroponics, spa, and aquarium water with one button for a hassle-free process.