inputs.text: great product price - bought 10 base stations hand held radio childrens ministry love absolutely zero interference easy hear simple volunteer use 10 rooms spread 3 floors every unit works flawlessly units sturdy reliable certain last yearsthere two reasons not give 5 stars first though says many subchannels not way program one unit receive one channel example thought could give classroom different channel let central desk receive every classroom not case therefore every room hears every communication every time not ideal case not showstopper secondly call button five different tones sound much alike not useful announcing major alarm planned use different sounds different messages 1 general announcehement 2 fire ehemergency etc unfortunately similar sounds using one general sound get everyone attentionwe used units replace walkie talkies quite happy upgrade rechargeable battery hand held unit much simpler base units plug wall saving money batteriesyou buy confidence work without interference not count thehem high tech