Titanium S1 with one probe is designed to monitor the water quality of RO/DI systems. It uses titanium probe, which performs excellent corrosion resistance. Magnetically-coupled controller makes it easy to install anywhere on a metal frame. With a ¼” Push Connect Union Tee (included in the package), it is easy to connect with RO/DI systems. Also, it is calibratable for accurate result. After 3 minutes of non-use, it will turn off automatically to conserve battery life.