***** **********Best Quality Guranteed. *****TD108 caregiver pager need to pair with nurse call buttons before use; senior press the emergency call button when need any help; watch tells nurse which alert button is pushed; then they can offer fast and precise service without waste time to find customer*****7 Prompt modes; wide choice of alerting sound; vibrate is strong for caregiver in night; beep sound is loud enogh for the servant in noisy environment; note; watch pager adopts durable and abrasion resistant LCD screen; and there is a extra film on the surface to protect the screen; you can tear it off before use*****Built in rechargeable 3.7V 380mAh battery and USB cable for watch receiver; 72H standby; long service time; compatible with most elderly alert call buttons*****100m or 328ft in open area; can penetrate walls in residential area; more suitable for upstairs and downstair to use; expand call button and watch receiver up to 999pcs; more suitable for large field to use; li