I'm getting the new 4g-5g unit - 2020. Reliable.
Let me correct previous incorrect statements (911 operator), and give review as a 6 year owner of this model unit. When you first get this unit, you need to call your local 911 system unit for a TEST of unit (after its fully charged). When you talk to the actual 911 operator for your area you need to inform them of the address this unit is to be registered to (your home address). If travel away from home, do a test in that area where your visiting to register a temporary address.  You should repeat this TEST every 90 days to insure both 911 system and this unit recognize each other. This unit does use GPS for locating you within 35 feet, unless obstructed like other GPS items gets obstructed by trees buildings and other things. You may experience this with your cell phone calls that are dropped. Many things obstruct signals, not necessarily the unit itself. Doing this TEST with your 911 local unit is like "pairing Bluetooth signals", so 911 will go to your registered residence directly, if it pings your in that 911 response area. If your not in that area another 911 system will locate you by repeat pings to your alerts button. You do not need to talk after activating this unit, standard protocol is 911will dispatch police to the button location because you could be unconsciousness due to medical emergency (heart attack seizure etc). This unit has been reliable for me and I intend to get their new 4g-5g unit coming out at end of 2020. I don't like an emergency service company deciding if I need help, I'd rather speak directly to 911 myself.  Having a unknowledgeable service company person ask a bunch of questions delaying the call to 911 dispatch could endanger me.
Rating: 5 stars