The A2 fits where readers have to: the narrow aluminum mullion beside a glass door. Behind the sealed glass face it reads standard 13.56 MHz cards and mobile credentials, with a light bar and beeper giving clear grant/deny feedback at a glance.
It wires back to the controller over RS-485 or Wiegand, so it drops into existing door loops as easily as new ones. The potted electronics take rain, salt air and casual abuse in stride.
