3 RRP: 441.99 Now: 274.99 Using only 3 buttons you have personal control over all the functions on the professionel 3e such as water throughflow, variable flow rate and so on. The electronics remember your personal settings and make the required adjustments. Thus you have the benefit of permanent system monitoring. It is even easier from a PC. With EHEIM Interface and the EHEIM ControlCenter Software you can control, monitor and update everything even more easily.