1,It is forged by zink alloy(stainless steel or copper) once, with high securicty and solidty nature. 2,Intellectual ultrathin little core of lock,This makes the breakage to the door as little as possible when making holes. 3,Free handle, to prevent the external stress from ruining the internal structure. The working life is long. 4,We test every circuit board to ensure its lifespan. 5,Lack of voltage indication to clew users should change batteries in time. 6,Emergency Cards or mechanical keys are used to open doors in special situtions. 7,Preserve the latest 256 records of door opening circularly. Knowing about the dynamic at any moment. 8,Ending the open functions of lost or oppointed cards 6pcs / carton, Carton weight : 18kg