Myron L has a unique, durable, field-tested design has evolved over more than 40 years, making Myron L instruments among the most reliable and popular of their kind in the world. The 750 & 760 Series conductivity and resistivity monitors offer high reliability at a low cost. The Aquaswitch System is designed to control the automatic switching of exhausted DI bank for a fresh standby bank. This is a complete exchange DI control system in a single package.