All Purvectors have the same protective effect, which offers 1,000 times more effective protection against germs than a surgical mask worn correctly at all times. The differences between the four Purvector types lie in the additional options that are possible, such as room scenting (from type 2), central display (from type 3) and additional sensors (from type 4) Purvector type 1: installation of Purvectors, which operate independently of each other, in a new or existing ventilation system, with the aim of 24/7 purvectorization. Purvector type 2: Installation of Purvectors and PurVect diffusers, which work independently of each other, in a new or existing ventilation system, with the aim of 24/7 or part-time Purvection and optional PURVect room scenting. Purvector type 3: Installation of interconnected Purvectors, which can be controlled via a central display and the PURVECT AIR app, with the aim of 24/7 or part-time Purvection, which can be monitored and controlled centrally, and optional PURVect room scenting. Purvector type 4: Installation of interconnected Purvectors, which can be controlled via a central display and the PURVECT AIR app, with the aim of 24/7 or part-time Purvection, which can be monitored and controlled centrally, and optional PURVect room scenting.