Power specs: Input 120 V AC; Output 16 V AC; 30 VA wired doorbell transformer; delivers stable continuous power; helps prevent low-voltage warnings, resets, and intermittent connectivity. Doorbell compatibility: Compatible with Nest Doorbell / Ring Video Doorbell / Eufy Video Doorbell; supports Nutone / Zmodo wired chime setups; reliable replacement for aging 120 V-to-16 V adapters. Thermostat support: Compatible with Nest / Ecobee / Sensi / Honeywell; constant 16 V AC power supply helps keep connected devices running 24/7 without dropouts or weak-power issues. UL Listed safety: UL Listed; high-efficiency design; heat-resistant materials; built-in overload and short-circuit protection; dependable long-term operation for always-on home devices.