The "Product Type" column on the Configuration > XBee Network and Administration > System Information > XBee Network pages of the ConnectPort X gateways WebUI is a user-configurable field which can be used to help identify various device types on an XBee Network.
ConnectPort X gateways will have their embedded XBee-PRO module listed as "X# Gateway" (# is the model number of ConnectPort X). XBee and XBee-PRO adapters also have the Adapter type pre-set in the factory.
In XBee and XBee-PRO RF Modules, this DD parameter is unconfigured. For those who would like to set or change the DD parameter, details can be found here