the fact that even the inner lighting of the phone was taken into account: the inside was not left completely dark, to avoid insects inhabiting the product. Materials The material of the telephone shell was acrylonitrile butadiene styrene (ABS), a thermoplastic polymer with high impact strength and glossy appearance. The use of plastics offered new possibilities as to the form and color of the product. References Other sources Lasse Brunnström: Svensk Industridesign – en 1900-talshistoria. (Norstedts) Telephony equipment Ericsson