Honeywell #TH4210D1005 Go to amazon.com Related posts Top 18 best pro4000 thermostat: Which is the best one in 2022? FeatureHoneywell #TH4210D1005 DescriptionPREMIER WHITE 24V/MILLIVOLT PRO 4000 DIGITAL PROGRPROGRAMMABLE THERMOSTAT 5/2 DAY.