1971: HT111   1972: Portavox   1975: HT311   1981: Vario 511  
1998: Vario 611   2000: Steel   2005: Classic   2006: iDor  
       

• 1971 – in-house intercom HT 111, sold over one million units

• 1972 – Video-Portavox, the first professionally designed Siedle product

• 1975 – HT 311, the first modular telephone and the basis for Siedle system design

• 1981 – Vario 511, the first modular communications system revolutionizes the market and spawns countless imitations.

• 1998 – Vario 611, the second and current version of the modular communication system

• 2000 – Siedle Steel combines modern system technology with aesthetic stainless steel or aluminium

• 2005 – The Siedle Classic combines features of the classical door intercom with modern design, modern technology and a wide range of material and surface variants.

• 2006 – Exclusive iDor Series inside units with slim line design. Includes audio only and audio/video units; easy programming extends the integration possibilities of all units in this series.