Ari Bike, an Italian maker of various aftermarket spider/chainring units and spiderless chainrings for a wide variety of crankset brands, has just thrown their hat into the oversized cog ring.
Offering three distinct models, they cover Shimano XTR M980 and XT M771 10-speed and SRAM 1030/1050/1070 10-speed cassettes. Like the others, these 40- and 42-tooth cogs sidle up next to the back of the cassette and require removal of the 17t (or 15t for some versions) cog.
Claimed weight is 70g to 73g depending on model. They come with a replacement screw for your derailleur in case a longer B-screw is needed to help the mech clear the new cog. Retail is €65, with delivery available in the US via express courier. Pics and links below…
They’re machined from ERGAL 7075T6 then hard anodized in an array of colors.