On Line Controls is the industry leading manufacturer and supplier of MicroAir regulators and motorized potentiometers. MicroAir, ultra low air pressure regulators and controllers for plastic tubing extrusion. Models MicroAir I, II and IV are high precision pressure regulators to control the OD of your tubing. Our Motorized Potentiometers and Motorized Rheostats are high precision proportional controls for automating analog driven devices. Through over three decades of experience, we have built the repertoire and expertise to fulfill every customer’s needs. The critical nature of our products functions requires the utmost in quality and reliability; both of which are exemplified in every unit we produce.