Yes, the DDDL 6.3 version can be used for the following DDEC versions: DDEC II, III / IV / V, all software versions of the MBE 900 and 4000 On Highway engines and DDEC Reports. It is said that the DDDL 7.0 needs to be installed as well for maximum compatibility. The seller states that both applications can be installed in case you need one of them.