Get a few KF94 masks from BeHealthy, Kollecte, or EverydayeMall (kid’s sampler pack) to try for size. Then order in bulk from Gmarket, which is the “buy now” Korean eBay and ships to the U.S. West coast in a week-ish and East coast in about 12 days.

Thanks to increased surface area, trifold masks are almost always going to be more breathable than equivalent bifold masks so that may be a consideration for you as well. I might suggest trying the Blue “Tiger Growl” KF94 trifolds, which you can buy individually on everydayemall, some Good Manner kids KF94 from Amazon, or some Bluna “Duckie” KF94 trifolds from Kollecte. If you really prefer bifold masks, these Cocomong masks from Kollecte could be a good option, or try these Blue bifold KF94s from Behealthy. Good Manner also has some good bifold masks, which come in XS (115mm tall) or S (125mm tall). Unfortunately you can only purchase them via Gmarket, but they could be a good bet if the Cocomong and Blue (both about 120mm tall) are slightly too small or large.

Adjustable ear loops are not the end all and be all, as non-adjustable ear loops are often more comfortable. Use cord stops, cinching lanyards, or s-hooks like this or like that to adjust/tighten masks as needed.

I would suggest not wearing cloth masks even outside, as COVID transmission still happens outside on a regular basis. Hopefully once you find well-fitting disposable masks, you can use those instead.

Oh that sucks. Yeah, the BOTN are no longer favored by BOTN wearers. Boooo!

You can easily make a non-adjustable ear loop adjustable with small cord locks like this. I actually find the “flat noodle” ear loops like on the Blue Tiger Growl masks more comfortable for all-day wear than the skinny adjustable ones.

The great news is now you have a size to work with to help find another similar mask, and many of them will come in black. The most important measurement to know for finding other similarly sized trifolds is the midsection height (the section that goes from the tip of the nose to the chin) and the overall width of the mask in millimeters. For a BOTN small, it looks like the midsection height is 65mm and the width is 180mm (though about 10mm or so is because of the adjustable ear loops).

Here’s a previous discussion of masks in this size range, which might give you some ideas. Or maybe start a new post asking for ideas for BOTN small but more reliable.