Please don't laugh- What are these called?

[catherIN]

I just got a hold of some backup Pentax K1000 bodies.They came with some extra lenses,flashes and some rings.I feel silly because I'm not sure what these rings are.Please be kind,don't laugh...at least not to hard.
One lens had a Gemini SkyLight 52mm on it.This is called a filter,isn't it? If not,what is it called? What is it's purpose,other than protecting the glass?
There was this small case that folds out.It's marked Hoya.There are 3 marked rings in it:
Hoya 49mm +1
Hoya 49mm +2
Hoya 49mm +4
What are these called?What do I use them for?Should they be used on certain lenses?
Will any of these effect my photos taken with my Pentax K1000 or Pentax K10?
I probably sound silly.Sorry
Cathy

[fx101]

Those sound like step-up rings. You would use those to use a larger filter (eg; 50mm) on a 49mm lens. The Skylight 52mm is in fact a filter, although on digital they are more or less used to protect the lens instead of the filter qualities.

edit: if they're lenses and not step up rings, then Xia_Ke is probably right. They sound like macro sets.

[Xia_Ke]

Nothing to laugh about at all Cathy, the only stupid question is the one unasked. The Hoya +1, +2, and +4 set is a close up/macro filter set. Skylight filters with digital photography have pretty much become a lens protector. With film though (for your K1000), they have a slight red/pink to them and will absorb UV light and help tone down a really sunny blue sky day, almost a slight warming filter.

[freygr]

There was this small case that folds out.It's marked Hoya.There are 3 marked rings in it:
Hoya 49mm +1
Hoya 49mm +2
Hoya 49mm +4
These are a DROPPER lens set for closeup photography.

Gemini SkyLight 52mm is a UV filter, unless you go up to the mountains it is a lens protector, but if you live in Denver CO then it has a use as a UV filter if you are using film.