These come in so handy around the house (and auto)! My headliner in my vehicle had some loose spots at the windshield, tried that spray on adhesive, no joy. Then I was wracking my lil grey cells, how to fix it without spending a lot on a whole new headliner. BINGO! Twist pins to the rescue! Worked like a charm and I don't have to worry about these guys failing. Once they're in, they're in! Found other uses within a few days and now I won't be without them!
Trust me, granny was onto something all those decades ago.....
It seems to me that they'd be great for some material but just didn't work for mine also success depends on what's under the fabric. I'm also getting tired of searching for conversion charts that interpret mm and cm speak. I don't speak meters and centimeters, this is America, we speak yards and inches. This wasn't the sellers fault it was China's fault, the seller did everything right, the item just didn't work.