Wireless wifi voice doorbell home remote intelligent self-power generation

Type A: One for outdoor use + one for indoor use [a set of 2 silver] Type 

B: One for outdoor use + 2 for indoor use [a set of 3 silver] 

C style: one for outdoor + one for indoor use [a set of 2 gold] 

D section: one for outdoor use + 2 indoors [set of 3 gold]

Other combinations can be combined, one for two, one for three, one for N, these can be matched