This gong the bell push is not energized (or only the 8V of transformers). Come out of the product description is not clear. The transformer thus always depends on the 230V mains and with the doorbell ringing separately connected it. Loud enough for us when the secretary is closed, however, it may sometimes be that you do not hear the ringing in the house. Simple Gong, pleasant sound, easy to assemble. 230V connection necessary.
