This assembly is specifically calibrated for Williams Floor Furnaces models 4505A and 6505A

This part number refers specifically to the venter wheel and disc

While designed for Carrier systems

meeting stringent RFI and EMI standards for reduced electrical interference

spring-return zone actuator engineered for reliable performance in critical HVAC hydronic applications

Siemens Building Technology 331-4811 Actuator 320720-756 This assembly is specifically calibratedFor veteran technicians managing air handler units and mixing boxes, the Siemens 331 4811 represents the industry standard for pneumatic reliability. This No. 3 Pneumatic Damper Actuator is engineered with a rugged, all metal body designed to withstand the harsh environments of mechanical rooms. Operating on a nominal 8 to 13 psi spring range, this unit provides precise, gradual, or positive actuation of HVAC dampers and air valves. The 331 4811