Review on 🔧 Adjustable Transparent 4-5CM Clear Suction Tightening by Chris Smotherman

I thought this suction cup would be perfect for my needs. I needed a tool to attach an external sunshade to our car's windshield. There is a metal grommet on each end of the cap and the description sounds like I could use a nut to attach a suction cup through this grommet. THIS FITS PERFECTLY. BUT . The nut had to be tightened to increase the suction power. Tightening the nut tightens the center of the suction cup, the tighter the nut, the stronger the suction. BUT . The sleeve for some reason did not allow the nut to be tightened enough to create strong enough suction to hold the cap in place. Without a suction cup going through the sleeve, it worked very well on glass, but there's no hook or tab in the design to secure anything. I suppose one could use a hook at the end of a small bungee around the base of the nut, but that would be improvisation at best. These mugs are coming back and I have to look for an alternative way to attach the lid. I was really hoping they would work.