4-in-1 Water Tester — handheld digital pen that measures pH, EC and temperature to give clear, actionable water-quality readings. Key benefits Accurate, reliable results: Built to deliver stable readings so you can trust your pH, EC and temperature measurements for decision-making. Compensation for changing conditions: Automatic temperature compensation keeps measurements precise even when water temperature varies. Built for frequent use: Sealed sensor probe and sealed battery cover make the tester waterproof and durable for field or indoor use. Easy to read and operate: Backlit LCD provides clear visibility in low light. Lock function holds a reading for review; auto-shutdown conserves battery life. Portable pen-style design: Lightweight and pocketable for quick spot checks wherever you work. What makes it stand out Combines multiple water-quality measurements in one compact, pen-style instrument for fast, on-the-spot testing. Integrated temperature compensation and a sealed probe improve measurement consistency and longevity compared with basic single-parameter pens. Simple controls and a backlit display reduce user error and make the device practical for both beginners and experienced users. Suggested applications Hydroponics and greenhouse nutrient management: Monitor pH and EC to maintain nutrient availability and crop health. Aquariums and pond care: Check pH, conductivity and temperature to protect fish and aquatic life. Pools, spas and basic water treatment checks: Fast spot checks to verify water conditions during routine maintenance. Features summary Functions: pH, EC and temperature measurement Design: Handheld digital pen with sealed sensor probe and sealed battery cover Display: Backlit LCD for clear readings in low light Convenience: Lock reading and auto-shutdown for energy saving Performance support: Temperature compensation for stable, accurate results This tester delivers a compact, durable solution for routine water-quality monitoring across multiple settings without complicated setup.