ring tones for different phones

There are a few ring tones I would like to download. They don't always list
the type of phone that I have (Motorola e815). They do list other Motorola
phones, including the e398 and e790. Are the formats of ring tones really
different for every phone model so that they must be individually tailored to
that phone or are they interchangable? Is there anyway to tell what type of
file they are? Are there any phones which share the same ring tone format with
the e815?

Thanks.

Jonathan
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Jonathan Sivier
Beckman Institute Flight Simulation Lab
jsivier AT uiuc DOT edu
Home Page: https://netfiles.uiuc.edu/jsivier/www/