HI 983311 Aqua Dip provides simple and fast measurements for EC/TDS/Temperature in places with high relative humidity. HANNA® offers convenience & accuracy in this tester. With only two operation buttons, Aqua Dip allows immediate and precise response in a concise design. This is a rugged unit that can be used again and again. The probe is even durable enough to be used as a stirrer. The HOLD button will freeze the display reading for your documentation requirements. Aqua Dip is factory calibrated and offers total protection against humidity, which makes Aqua Dip ideal for field use.