Product review (5 stars): Fits Great Stanco Bowls
I bought these because they were the only ones that had 3 slots showing in the bowls and didn't cost an arm and leg.  I was worried they wouldn't fit based on other reviews but guess I am one of the lucky ones as they fit perfectly.  My stove is a Frigidaire about 15 yrs old or older (I rent so I don't know actual age).  Oh, as I type this, I've only tried the larger ones first so don't know if smaller ones fit.  I also inserted foil protector inserts after plugging in the burners.  Still fits great.