Here we have a CPC Phase 2 28/2.8 MC Macro in Nikon mount. There is a review of the non-macro version in K mount
CPC Phase 2 MC Auto 28mm F/2.8 Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database where it is stated that a CPC is a Cosmicar. There is a thread
What is Cosmicar ? - PentaxForums.com that establishes that a Cosmicar is a Pentax. So this is a Pentax in Nikon mount, complete with Nikon ears and a 52 mm filter thread!
I have the original box and it shows CPC to stand for Combined Products Corporation. My sample was made in Korea, though most of them mentioned at Pentax Forum seem to have been made in Taiwan. Amusingly, the lens has a yellow sticker that looks almost identical to the JCII inspection stickers that all us old guys fondly remember from our film days. But this sticker says "Quality|Passed|CPC.
I've taken a few shots with mine and the image quality, at least at close focus, is excellent.