C-wire requirement flexibility

#1
Reviews say the thermostat can be installed without a C-wire, though another notes you can still use a common wire if you have one.
#2
The included power extender kit is framed as helpful for setups that do not have a common wire.
#3
The thermostat still expects a common wire, but the supported adapter path makes installation more flexible than a strict C-wire-only design.
#4
Reviews suggest the wiring is friendly when replacing a similar smart thermostat, but homes without a C-wire may need extra hardware.
#5
Every installation-focused review says a C-wire is required, though several note separate adapter or extender-kit workarounds.