CR20 Series are accessories designed to read (CR20E/M) & write  (CR20M/W) proximity cards. They are connected to PC through USB Port (Plug & play). They allow high speed transactions and incorporate LED indicators. CR20M/W includes communication protocol for development and it’s compatible with S.O Windows 32 bits. CR20E and CR20M are compatible with windows S.O and read the same serial number as ZKTeco devices.