1. Adopt U type handle to prevent the accident 2. Stainless steel crust, never rust 3. Don't install the motor inside the mortise: change the deadly disfigurement of motor at all 4. Free rotating handle, maximum prolong mechanism life and also avoid unlock by violence 5. Pure stainless steel mechanical rotating structure enable for using more than 10 years 6. Change batteries in the lock most easily and safely. 7. Adopt plastic insulated protection on electronic part