Bought off ebay, poorly listed, brushed with sandpaper. Just polished a little bit. Looks CNC machined to me, light too (450 gram shown on post scale) Two piece drive arm. 110 BCD. Never seen these before. I cant find any informations about it. Checked all GT catalogues, internet and nothing. Cranks shown in catalogues looks different. Thought they may be some odd downhill versions, but granny ring could be installed so they're not. Any thoughts?