RS232 Shield is a standard communication port for industry equipment; This module is base on MAX232, which is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5-V supply; The shield integrates DB9 connectors (female) that provide connection to various devices with RS232 interface; Also the RS232 headers will facilitate your connections and commissioning; It provides the welding areas to make full use of extra space on it, which is highly convenient for prototyping.