Robertshaw® Thermostat, Series: Value, 24 VAC with Battery Back-Up, 3 VDC Battery, 1 - 3 A, Auto Changeover, 2 Heat/2 Cool -Stage, Temperature Settings: 45 - 90 deg F, (2) AA Alkaline Battery, +/-1 deg F Accuracy, Battery/Hardwired Power Source, Horizontal Mounting, 5-1/4 in W x 3-3/4 in H x 1-3/16 in D

• Auto changeover - switches automatically between heating and cooling for constant home comfort
• Pop-up wizard - launches instant installation menu to quickly enter the settings for programmed thermostat functions
• Worry-free memory retention - maintains setpoint and programmed parameters, even during power outages
• Easy change battery access - provides drop down removable compartment for quick battery replacement
• Circulating fan - maintains optimal air circulation between demand cycles for improved comfort with minimal energy use
• Low temperature freeze protection - turns on heat automatically when temperature goes below 41 deg F, protects pipes from freezing
• Adjustable temperature differential and upstaging - provides for full selection of parameters to deliver maximum comfort or energy savings
• High and low setpoint limits - protects the heating and cooling systems by limiting temperature settings

• Specification Sheet https://assets.unilogcorp.com/267/ITEM/DOC/Robertshaw_RS4220_Specification_Sheet.pdf