What is the difference between the XNT 9 DI T and the XNT 9 DI T (RD) down imaging transducers ? Thanks.
The RD is "Re-Designed" ... HB changed the way they fill the housing with epoxy ... 
There's no difference in functionality ... 
There is difference if buying a Transducer Shield and Saver bracket for that xducer ... 
Rickie