Display of time date in the system Wall-mount or for desk top use. Built-in real time clock (RTC) module Programmeable with PIN (Personal Identification Number) Provide RS 232 RS 485 TCP - IP USB Communication Interface Memory Capacity : 50000 capacity. User Capacity 1500 Finger Prints Sensor : 500DPI Optical Sensor U R U 4000B 500DPI Optical Sensor Options : Card + Finger, Finger + Password, Finger Card only.