Besides sensors, the Wiegand effect is used for security keycard door locks. Newer keycard systems use radio-frequency identification (RFID) technology such as the TLJ infinity. Linden secretly procures the missing keycard, which opens the door into the Richmond campaign office. The detectives try the keycard at Mayor Adams' main office, but the door remains locked. Residents also receive a keycard which gives them access to their apartment and storage. When they try the keycard at Richmond's main office, the door opens. The Intelligent Keycard also acted as one's hotel room key. A half-way house between standard Blackwood and RKCB is Keycard Blackwood. Back inside, she notices a keycard from City Hall between some exposed floorboards. However, Chloe steals his keycard and escapes from detention. The blood-stained City Hall keycard lies unnoticed under the floorboards. Drake tries to use his keycard to open it, but it rejects the card. When asked about his keycard, he shows it to Holder. Jackson then makes a phone call to tell someone the police has their keycard. Mr. Glass is also executed for giving Laina his keycard, even though he didn't.