Flip a model?

Well, i got a model but i want it to looks like if it where in front a mirror. Something like this:

Mirror modifier
The object is mirrored about its origin or add an empty to use that as the mirror axis

Sorry, my english is bad, can you explain it a little more detailed?

Go to link and read the wiki.
Add the mirror modifier, properties panel under spanner icon
Mirror modifier tutorial http://blenderdiplom.com/index.php/tutorials/item/91-ressource-blender-modifiers-explained

The settings are pretty clear

This is not what im looking for, the video teachs how to MAKE a model with the “Mirror Modifier”, but i just want to flip horizontally my model from this:
to this:
not making a new one or making a symmetric model a just want to flip it horizontally.

As Richard said, you can do that with the mirror modifier. Or you can duplicate the object (shift+d) then scale -1 on the x axis (sx-1)

Or Object / Mirror menu entry (Ctrl+M)

Thanks a lot!

Thanks thats what i was exaly looking for ^^!