This Rosemount 222 Toroidal Flow Through Conductivity Sensor is a reliable and efficient tool for measuring conductivity in various applications. It is manufactured by EMERSON ROSEMOUNT, a trusted brand in the industry. This unit is sold as a single item and is made in the United States. The sensor is designed for easy installation and use, with a compact and durable construction that ensures long-lasting performance. It is suitable for a wide range of tests, measurements, and inspections, making it a versatile addition to any business or industrial setting. California Prop 65 Warning does not apply to this item.