We bought this part after planting a new hedge Thuja (40 meters long). Connected thereto was a Perl / drip hose with pressure reducer. The device acts wertig is intuitive and use and very reliable. The required 9V battery should hold approximately 1 year. The device can also be coupled to a humidity sensor or a "weather alarm" from Gardena. These accessories go again into the money and in my opinion are not necessary. Since I could not see any disadvantages and the time-consuming "manual" pouring the hedge no longer - strong buy recommendation from me!