Four-Door Ultra Access Controller, supports 100000 Users, 10000 Fingerprint, 200000 Cards, 600000 Events, supports 4 Door Control. It can extend up to 62 DS-K2M002X Access Modules, and up to 128 Doors can be controlled. Downstream RS-485 Redundancy Wiring Design to ensure Communication Stability. Web Configuration Management. 1× Network, 4× Lock Control, 4× Exit Button, 4× Door Contact Input, 8/4 Alarm IO, 1× Tamper, 7× RS-485, 4× Wiegand (standard 26/34 Input), 1× USB 2.0, 1× Fire Alarm, 100~240 VAC Power Supply. Supports 12 VDC / 7 Ah Backup Battery. Wall Mounting Installation.