I have for sale a pair of chainrings (and chainring bolts) from AbsoluteBlack that can convert most Shimano road double cranksets which use 4-bolt 110 BCD spacing to subcompact gearing (48T/32T). They are anodized black in color.
AbsoluteBlack lists compatibility with the following cranksets/drivetrains:
* Shimano Dura-Ace 9100, R9120, R9150 & R9170 Di2
* Shimano Dura-Ace 9000 & Di2
* Shimano Ultegra 8000, R8020, R8050 & 8070 Di2.
* Shimano Ultegra 6800 & Di2
* Shimano 105 R7000, R7020, R7070
* Shimano 105 5800
You can find more details about these chainrings along with instructions on how to install them (including videos) on AbsoluteBlack's web site:
https://absoluteblack.cc/oval-road-chainrings-30-46-and-32-48-for-110-4bcd/ Here's a review of the sub-compact ring setup by BikeRumor:
https://bikerumor.com/2018/07/03/review-absoluteblack-sub-compact-oval-chainrings-48-32-and-46-30-with-shimano-ultegra-cranks/ I bought these directly from AbsoluteBlack in Poland, and never opened or installed them. I ended up getting a new crankset instead, and the return process to ship these overseas turned out to be a big pain, so I'm selling them at a loss instead. They are still in the original packaging.
I originally paid just over $220 for these, and will sell them for $180 + shipping firm, payment via PayPal or local pickup in Portland, OR. DM to arrange purchase.
