BTX CD-MX9F MaxBlox 9-pin DB9 female to screw terminal connector for RS-232 or RS-422 control. The MaxBlox Solderless DB9 EZ termination system features a patented design that is better, faster and stronger than anything else on the market. Manufactured with genuine Phoenix Contact terminal blocks for a truly reliable connection, these larger blocks make it easier to terminate while still keeping the connector compact.