Simultaneously max receive calls from 99 call beds or toilet extensions
Without interruption Call: Regardless of being standby or in ringing condition, it can show the number and information of extension
Extension Call Storage by the Host when the call is not pick up by nurses, the call numbers will automatically be reserved
Three class illness: critical, serious, cured indicated by red,yellow,green light
Host machine Hand-free: Host can speak with extension by hand-free when extension call host 
Ringing volume adjustment: the ring volume can automatic change over in day and at night