I have a Unikas UF-10k filter I purchased some time ago and never used I. Started to install it and there are no fitting in the package. I am assuming I lost them but it says the nipples are exclusively for either in or out. Anyone have any ideas where I could find these fittings.

Try this site:
http://www.defender.com/product.jsp?path=-1|311|2349059|2837510&id=1070536

your hardwhere store should sell them also just take it in with you

looks like they are special fittings..don't know why they do that , but I'd get a more common type..

the fittings are shown at the bottom...
http://www.defender.com/product3.jsp?path=-1%7C311%7C2349059%7C2837510&id=1212742

I have to agree. It would appear that the fittings must contain some type of check valve that only allows flow in one direction. I can see that as a potential disaster with a failure at the worst time. A Racor would be a much better choice as it allows either side to be input or output and it uses standard NPT/barb fittings for the hose connections with no internal restrictions.