The filling of water and subsequent insertion of the tank is a cumbersome thing. If one takes the tank, the water is in the lower part of the device and threatens to run out at the smallest touch. If you have the lid of the tank to rotate not fixed, the water trickles out. (As far as the Technical) The built-in hygrometer gives only the results in the area of the device known. Optical is one of the "Geblinke" display on the biscuit I have returned the device.