Further information for Telecom Behnke BT 20-423 - Door Phone Series 20 "industry standard" (2x horizontally)
Door Phone Series 20 - industry standard (2x horizontal) Consisting of: - Small basic electronics for phones with integrated electronics (up to 8 RT 1 TWB, 1 LP, 1 MIC, 2 BO, 1 AL, 1 VID electronics extension not possibleness). - Module with Lautsprec : Aluminum