Horizone Horizone provides the ultimate in versatility. This space can accommodate your fish kettle, your large pots, or even several containers. It can be split into 2 independent cooking zones while maintaining an optimal temperature distribution. Ultraboost Function The ultraboost function allows the hobb to quickly heat up. The heating process can be up to 20% faster than the classic boost function. Piano Function The dedicated "piano function" key, pre-programmed, divides the horiZone space into two distinct powers. The front zone allows you to grasp the food and then keep it warm by sliding the container over the rear zone.