2 Husky part numbers for one part ?

[kirko]

Hi Gents ,,
anyone in the know on husky trimmer parts ?
here are 2 part numbers that seem to refer to the same part ?
578447001 and 544909101 am I missing something ?im sure there must be a difference in these 2 parts but I am not sure what it is ?
Help needed,,
Thanks in advance Kirko

 

[ANewSawyer]

When I do a parts search on my preferred part site this is what I get:

http://www.partstree.com/parts/husqvarna/parts/578447001/

This kinda looks like a Jonsered part #.
http://www.partstree.com/parts/search/parts/?searchTerm=544909101