Don't be misled by the 1 star, I initially LOVED this product however, caveat emptor.

I bought these in Nov of 2016, using 1 in our 03 Jeep Sahara, the other in our Ford F250 Super duty, Lariat. I'm including the models as this is the major problem with these mirror hangers and many newer vehicles. They are magnetically attached!! Our other vehicle is an Eddie Bauer Explorer which we never used these holders in, had we used then the same problem would have occurred.
Problem you ask? THE MAGNETS make the compasses cease to function!! Like I said initially I really loved the ease in how these holders attached & reattached. I spent countless hours trying to figure out why the compasses had died in both these vehicles. I spent hours trying to recalibrate the F250 per manufactures instructions, driving around in circles on many different occasions. The Jeep just had a "# # # # #" screen so I thought it has simply frozen in the N Idaho winter.

I just happened across the solution when I just hung the hanger on the Jeep in full 75 degree sun and it again the compass went out again. This am I removed the hanger in the F250 and it calibrated in less than 2 circles.

If you have a newer vehicle almost certainly you have a compass, if you rely on that compass forget these holders, just FYI.

When I first saw these I know I needed them. I am actually using mine for hang tags of a secure parking area. The original tag was laminated paper and forever falling apart. This tag solved that and it's easy to take on and off as I come and go. One for me and one for the hubs who has a Jeep. His is a little long but that doesn't stop us from using them.

The absolute best for use and protection of your handicapped tag. The old ones I used were always breaking off at the hook part. With these, you leave the hook on your rear-view mirror. When needed, you put the plastic-encased tag on the hook. Easy. You just put it near the hook. It grabs onto the magnet easily. Easy to put on and take off the magnetic hook. You'll wonder how you lived without it. I think it will last forever.

Much better than the traditional plastic sleeve - living in Az, the traditional sleeves warped in the heat in such a short time and the hook would always break off in no time, we were always having to replace them almost monthly, but we have been using this sleeve for several months (including the hottest months) and have had no issues with warping or melting, the hook is a stronger thicker plastic and the magnetic snap makes it easy to attach and remove the placard sleeve, unlike the traditional sleeves where you had to remove the entire sleeve and hook, would definitely recommend to anyone needing a placard sleeve and we have purchased several more for friends and family

Great holder. Magnet strength holds up and holder does not warp in high heat.
Bought this as a replacement for my father's standard plastic hook holder in which the hook was breaking off. It seemed to make sense to get this type of holder both because there wouldn't be as much stress/wear and tear on the hook part and it should be easier to take on and off with the magnet effect.
This turned out to be the case. The magnet gimmick was just the right trick. The magnet is definitely strong enough to remain intact through out hanging on the hook for several hours to overnight. This includes in high heat and strong direct sunlight.
Likewise after using it for several weeks in high heat (100+ temp and probably more like 120 - 130 in car) and strong direct sunlight, the plastic did not warp or shrink. This was, however, with some factory window tinting, but not dark.
My father really likes it and especially for the ease of putting it up and taking it off. After we practiced together we found the best way to keep it on without fail was to make sure to grab the magnet with as much surface for both pieces as possible. Then a simple light twist and tug separates the pieces easily without struggle. My father especially likes this because he doesn't have to tussle with getting the hook on/off of the rear mirror stem. He liked it so much he gave the spare (there's two in a pack) to his girlfriend. And she's found the holder to be of the same benefit.
So for the value as almost a two for one product it's well worth the cost for the quality and ease of use.
Product is top notch after a couple of months of use and seller delivered on time and as described. Good transaction.