Black telephones in Mr. and Mrs. Sonneveld's bedroom. These are tabletop telephones, intended for indoor telephone traffic. Shortly after the family moved in, as many as twelve sets could be found: two sets for public telephony and ten home telephones. The telephone was part of Siemens and Halske's house installation, which consisted of black wall models and black and white table models. A house system in itself was not a modern invention, it was usually purchased in companies, for private use it was a great luxury.