Summoning devices for assisted living/nursing home facilities?

One of our facilities has been relicensed with 24hr Customized Living, and part of the requirement is for all clients to have a summoning device on them, in the event they need staff assistance due to a fall, health issues, etc.  Does anyone have any recommendations on a call/summoning system that is reliable?

I'm finding some options that are either extremely expensive or cheap and appear to not be very durable/reliable.  If anyone has any input, we would greatly appreciate it.

Thanks!