Zonefirst ZDS-18X16 18WX16H Parallel 24V 2-Pos S/R R-410A if you need the version

if you need the version with the pilot mounting bracket

What is the purpose of the included retaining ring

as this thermostat works in conjunction with the safety valve system

this genuine ICP part includes the valve body

Zonefirst ZDS-18X16 18WX16H Parallel 24V 2-Pos S/R R-410A if you need the versionThe Zonefirst ZDS 18X16 is a heavy duty, side mount rectangular zone damper engineered for precision airflow management in 24V zoning systems. Featuring an 18W x 16H extruded aluminum frame and parallel blades, this unit is designed for a side mount installation where the motor is located on the height dimension. The parallel blade damper design utilizes 3" blades pivoting on self lubricating bushings, ensuring silent operation and a long service life