Extend the connection between your db9 serial devices by up to 3m the mxt1003mbk black serial extension cable 3m features one db9 male connector and one db9 female connector providing a high quality extension for your rs232 serial devices which enables you to position your peripheral devices as needed expertly designed and constructed of top quality materials to ensure durability this db9 extension cable is backed by our lifetime warranty the startechcom advantage allows you to extend the re