Has worked flawlessly. No connection to internet or home Wi-Fi. Once the programmer connects wirelessly to the two thermostats it is generally rock solid. Consist of. - Programmer - Wireless receiver - Wireless room thermostat - Wireless cylinder thermostat uses the same space and strap as the old Honeywell mechanical thermostat Note I have pictured a Honeywell wiring centre. The idea is that you cut links depending on your configuration. I changed configuration so some links were cut then resoldered. You are welcome to it but consider it a free gift. Thanks