door bell

Rima Sabina Aouf describes a "minimalist" door bell in Dezeen.  Just launched on Kickstarter, the "Ding" door bell provides a wireless door bell ringing and answering system.

The system consists of a button, which is hung on or near the door in question, and a speaker, which emits the chime.  Both components have been simply styled, appearing as almost featureless rectangles with circular ends: