The Duff Norton TMD02-1906-4 Linear Actuator is an electromechanical device designed to provide controlled linear movement using a 12 VDC power supply. With a 250-pound load capacity and a 4-inch stroke, it converts electrical energy into straight-line motion to position or adjust compatible mechanical components. It can be used in HVAC dampers, ventilation systems, and equipment requ... https://www.partshnc.com/duff-norton-tmd02-1906-4-linear-actuator-12-vdc-250-lb-4-stroke