Further information for Telecom Behnke BT 20-112 - Door Series 20 phone industry standard (3x normal)
BS 20-112 consisting of:
1x 20-0001-BS basic electronics size 3 for a hybrid telephone (= analog and SIP telephone)
1x 20-4310 Frame size 3 vertical
1x 20-1100-BS Module with loudspeaker size 3
1x 20-2023-BS Module with 2 call buttons with labeling fields
1x 20-3100-BS Module with microphone