Three-in-One Functionality:This product offers a comprehensive solution for water quality testing, combining the functionality of three separate devices into one compact and convenient tool. High precision: The measurement range of this device is 0-990ppm, which can provide accurate and reliable results, ensuring that you obtain the most accurate water quality information. Widely applicable: Whether you are a professional or a DIY enthusiast, this water quality testing pen is suitable for most situations. Compact and Portable:The compact design of this water quality testing pen makes it easy to carry around, perfect for on-the-go use. It's a practical tool for both home and travel use. Easy to Use:This water quality testing pen is user-friendly and intuitive, making it accessible to everyone. No special training or qualifications are required to use this device.