Mamiya RB67 - K lenses?

Have been googling and not coming up with the right into. For an original RB67 Pro (non SD) I can use K lenses? K lenses are the same but better quality control lenses? Suggestion I should get K and not the older ones? Is this the K lens or is it the K/L lens?


Thanks.

Check out this site: http://rb67.helluin.org
They've got info on all the lenses too.

Also this: http://www.reznitsky.info/Mamiya/Comchart.htm [even though it's more of an RB/RZ compatibility, it does list the RB lenses.

and here http://camera-wiki.org/wiki/Mamiya_RB67