what are these called and where can I find them

they aren't sill plates for sure , they are called carpet hold down molding or trim. They hide the wires and hold the carpeting in place. While these are called Sill plates, Scuff plate or threshold plates. I make replacement sill plates (custom or the boring stock shaped ones) and may be cnc'ing a master for those carpet hold down plates if I can ever get some of my other stuff done..

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what are they called. Carpet trim pieces or do they have a particular name.
https://www.classicindustries.com/product/mp14009.html

Ive seen them called both but I believe the proper description is door sill plate.