The ONE2 is a versatile air-to-water heat pump available in five performance variants. It is primarily designed for outdoor installation, but is also available in a version for indoor installation.

The heat pump operates in ON/OFF mode, which means that it does not have continuously adjustable output, but operates in on/off mode. It is suitable for domestic hot water (DHW) and for heating or cooling, thus ensuring a comfortable indoor climate. De-icing is achieved by reversing the cycle, providing effective frost protection. The pump also offers the option of cascading, allowing increased performance by connecting multiple units. It is designed for buildings with heat losses up to 50 kW, outside of a cascade configuration.