The filters you need are located on the following page:
http://www.waterfilters.net/culligan/reverse-osmosis/Culligan-H30S-R.htm
The first two stages go in the black housings you were talking about.
There is also a third stage post-filter that does not go into a housing but is installed after the black housings. Some systems do not have this 3rd stage post-filter so you'll want to check your system first to see if you have it.
Thank you,
WaterFilters.NET