I bought a sprocket from AliExpress.
It's a 12-speed sprocket with an 11-32 configuration, but it has tight gear ratios at 1t intervals from 11-17t.
My FTP is 250 watts and I mainly use around 230 watts on flat terrain. If I choose 32 to make climbing easier, there's a drawback of jumping from 16t directly to 18t, and if I choose 34, there's a drawback of jumping from 15t to 17t.
For those with similar power to mine and FTP in the early 300s range, 16t would likely be used most frequently. Having gear ratios that allow 1t shifts up and down, and being able to choose only one of 17t or 16t, creates a significant efficiency difference in flat terrain riding.
That's why I think a combination that allows choosing both 16t and 17t without sacrificing the 32t is very appealing.
The price is just under $20, which is about 30,000 won, and considering a 105 sprocket is around $33, it's not exceptionally expensive for an AliExpress product, but considering the unique gear ratio with 16t, it seems to have some merit.
The weight is 350 grams with steel lock rings, and if I replace them with aluminum lock rings, it would lose a few grams and be similar in weight to the 11-34t 105 at around 360 grams.
The cog material is steel and the spider appears to be aluminum, but it's not light regardless.
The ramps for shifting have 1 engraved on small cogs, 2 vertically on medium cogs, and 4 on the largest cogs.
The design is slightly different from Shimano cogs, but the shifting performance itself doesn't seem to have much difference, though the finish leaves much to be desired.
I saw some burrs, so I smoothed them out a bit with a file.
Here are a few photos.
