5 pcs MAX3232 RS232 to TTL Female Serial Port Converter Module DB9 Connector to

1.On-board MAX3232 serial communication chip. Introduction : This is a small RS232 to TTL serial conversion module, suitable for all 3.3v or 5v target devices. This is small RS232 to TTL level serial converter module, suitable for any 3.3v or 5v target devices.Built-in SP3232EEN chip,fully compatible with existing legacy COM port software.

eBay