Why do renters have to pay a deposit of 500 to get an electronic access card?

In order to prevent tenants from losing their access cards. Basic definition of access card The original intelligent access control system consists of a host, a card reader and an electronic lock (computers and communication converters are added when networking). The card reader is a contactless card reader. Only when the cardholder quickly swings the card near the card reader (5- 15cm) can the card reader sense that there is a card and guide the information (card number) in the card to the host. The host examines the illegality of the card before deciding whether to close the door. The purpose of letting renters pay 500 yuan deposit when they receive electronic access cards is to prevent renters from losing their access cards and causing hidden dangers to the security of the community.