Hi you can switch between up to four cameras with this model Motorola MBP855 - Art-Nr 6366960. I am now looking for additional cameras.... but I can't find the same model. Possibly Motorola MBP 88 - item no. 6532285? On the back of the Motorola MBP855 - Art-Nr 6366960 there seems to be an additional sensor, which is not visible in the pictures of the MBP 88 - Art-Nr 6532285. I ask for support. THANKS