Question about Doro 3500 Alarm Trigger

According to the manufacturer, all Doro smartphones are compatible with the Doro 3500, except for the models 740, 745 and 810. You can find all smartphone models from Doro that should fit under the following link: https://www.digitec.ch/de... . We also have a set with the Alarm Trigger and a Doro 8040 smartphone. You can find it under this link: Doro 8040 + Alarm Trigger (5", 16GB, 8MP, Graphite)