It's been hard to gather them all upSorry to say so - but as I recall it, that one belongs to a model "family" that sort of was a "low point" in the Jonsered(s) story - and represent Jonsereds attempt to design lighter and less costly saws than (most of) their 1970s saws themselves. This lead to rebranded Partner saws being sold as their smaller "pro" saws for a while, starting with the 490.
I believe they work quite well though, as long as they work, but aren't so easy to get right in the long run, as there are more places than usual where they may start leaking air?
http://www.acresinternet.com/cscc.n...801048d6175e831988256b6b00189180?OpenDocument
The 450 is my late brother in laws now nephews.
But i believe i own most every saw you don't like
and i have a dolmar 115 lol