You will need this adapter to affix the Panasonic Close-up lens and Tele-photo lens to your Lumix FZ40, FZ45 or FZ100 camera, it is made of tough but light-weight aluminium, it's not quite in keeping with the look and texture of the FZ range but isn't a massive problem (just one of vanity).
Unlike the lenses this isn't made in Japan, it's manufactured in China... this however doesn't seem to have had an affect on the usual Panasonic quality standards.
I can't really elaborate any more, it does the job for which it was made to do and is essential if you want to increase the capabilities of your Lumix camera.
Thanks.