The Honeywell Home Sundial RF2 Pack 1 (Y9120H2009) delivers energy-efficient heating control with TPI (Time Proportional & Integral) technology, compliant with Boiler Plus regulations. Featuring 2-way wireless connectivity at 868 MHz with a 30 m range, pre-bound from the factory for easy setup. Operates between 0–40°C, IP30 rated, and includes ST9120C powered by 230V AC and DT92E with 2×AA batteries. Supports wireless enable upgrades and comes with a 5-year warranty.