**Look Keo 2** and **Look Keo** are Look's current/previous range and they are compatible with each other.

**Look Delta** are Look's earlier range. I'm afraid they are not compatible with Keo's or Keo 2's

**SPD-SL** are Shimano's version of road pedals. These aren't compatible with Look products, neither are Look products compatible with them.

Checking out [Look's web site][1], you don't see Delta pedals on there any more, but if you look at the various Keo pedals, they are clearly a different shape to yours.

Doing a quick web search for Look Delta reveals several images, including some on [this page][2] (Exustar pedals which are compatible with Delta's - I haven't embedded the image in case there are copyright issues). These pedals look pretty similar to your's, what do you think?

If you argee, then you need Delta cleats. Or cleats which are compatible, for example Exustar. An eBay search is probably worthwhile.

  [1]: http://www.lookcycle.com/en/us/route/pedales.html
  [2]: http://www.sjscycles.co.uk/exustar-e-pr70-look-delta-pedals-prod24021/