Do I need an adapter for this fisheye lens attachment?

I have a Nikon D3000 with 18-55mm lens. Will these fit or I need an adapter?

http://www.amazon.com/...002Q10Y9I/

There's no way to tell.

The advert does not list the filter thread size. Your 18-55 mm lens uses 52 mm filters.

Look instead for an add-on "fisheye" filter with 52 mm threads and one that is.25x to give you a better chance of actually getting a 180 degree fisheye view