In late 2009, these two models were modified to be more robust in a mobile environment and to tolerate a wider voltage range (5.5-30V) and power spikes (up to 600V). Also, the newer variants do not require an external fuse.
Functionally, they should all be identical, i.e. regarding installation and use.
Regarding the Hubport/4c DC: 301-1010-44 is a redesign of the older 301-1010-42.
Regarding the Hubport/7c DC: 301-1010-78 is a redesign of the older 301-1010-72.
Last updated: Aug 08, 2017