Further information for Telecom Behnke BT 20-111 - Door Phone Series 20 "industry standard" (3x normal)
Door intercom phone 3x vertically Consisting of: - Large basic electronics for phones with integrated electronics (up to 8 RT, TSR 1, 1 LP, 1 MIC, 2 BO, 1 AL, 1 VID electronics possibleness extension). - Module with Speaker (Size 3 = large). - Module m : Aluminum