1.The lock is made of pure brass and is very durable. 2.Use Siemens encryption techniques which is of high security. 3.Can register 255 exclusive user cards. 4.Convenient for hotel use. Basic Parameter Weight :3 kg Color :Golden or Silvery Working Temperature :-40C to +70C Working Humidity :10% to 90% RH Card Type :SLE4442 Reading Speed :< 0.3s Transaction Capacity :900 transactions User Capacity: 255 users Pack Volume :280mm*140mm*100mm Electric Parameter Input Voltage :DC6V Input Current :200mA Dynamic Current :150mA