Setra 2641R25WB11T1F Trans 326058 757 This kit is a non negotiable This kit is a non negotiable solution for modernizing older ClimateMaster or Carrier branded geothermal systems without requiring extensive cabinet modifications The Armstrong International A8581 Humidistat (also known as the A 8581) is a high performance on off high limit duct humidistat designed for precise safety and control in industrial and commercial HVACR applications ensuring reliable duct static pressure readings over time this Model 264 pressure sensor utilizes a tensioned stainless steel diaphragm and a capacitive glass substrate to ensure superior long term stability and resistance to mechanical shock