UHPPOTE Full Complete Metal Shell Case 125Khz ID One-door Access Control Machine Unit With Electric Strike Lock 3A Power Supply Remote Support 500 standard users Can be used as a stand alone keypad.Doesn't need to connect on the computer,can works alone Support entry modes: Password Only / ID Card Only / Password + ID Card With lock relay output, secure / normal Mode, NO / NC output Built-in bell button can connect a external bell