Dremel 426 1-1/4” Fiberglass Reinforced Cut-Off Wheel. Also look at 456.
I also have a package of Chicago Electric 1-1/2” Rotary Cut-Off Wheels. Chicago Electric, of course, is a Harbor Freight product. It’s marked Item 34749. I’ve never used them, the package is unsullied by human hands.
I used to have (and think I still do, somewhere) a pack of “The Good Ones” but I cannot locate it now, but if you Google Cut-off wheel 1/16” arbor, you’ll get a goodly number of non-Dremel choices, but getting the 1/16” hole is a tough search.
But you can always go to McMaster-Carr, and look for cut-off disks. Look at the selection of disks for Dremel. There are a number of specific-purpose wheels at different diameters, and some are “Fiberglass Mesh” reinforced. Reasonably priced, a package of six 1½” disks, is $9.98, plus some shipping. You’ll have it by Monday or Tuesday.
Hope that helps you out.