1. The special and pleasant sound of the doorbell has several bel cantos for all people to choose. 2. Delicate streamlined appearance shows the special tastes of the host. 3. Up-dated intelligent flash light design brings convenience to hearing handicapped. 4. Ultra-distance represents the technology of surpassing obstacles. 5. Wireless easy mounting design never affects your inner decoration and makes the doorbell any where you like. 6. All day long anti-interference system pretends the doorbell from interference ouside or between neighbors. 7. Energy saving desgn of environment protection the battery inside the button can last for on year(20 presses per day. ) 8. Delicate smart part makes the doorbell a saluting angel of dwelling house. Work building, hotel, building factory. And so on...You will never miss any guest.