NIUBEE Acrylic Window Sign Holder 8.5×11 Inch with 4 Suction Cups for Glass Window Wall Mount, Advertise Display Office Store Promotion Picture Frame for Mall, Office, Restaurant (8.5×11in,2pcs)

Don't know the long term durability of the suction cups but initial impression is very good.

We use these in the window of our small business to notify our customers that we have a notary onsite. We've had them up in the window for about 2.5 months now and the suction cups are still going strong and the acrylic is still clear as day with no cracking or yellowing.

The acrylic is very brittle and prone to " Cracking " on the insert corners. The one in the photo arrived broken during shipping. Fortunately it is not visible once inserted in the base. Be gentle with them.

I used it for my windshield and it happens to get broken in the first attempt (left side corner) after I was adjusting the suction cup and later on the right suction cup did not stick to the windshield. Not a good experience overall, the money spent was not worth it at all, as at the end when you buy the two set, you will be more scared the second set will break as well.

Description claims that the item is waterproof. And while that’s true, acrylic is definitely waterproof, the paper that you put inside is not waterproof. I bought this sign for outdoor use and I can absolutely not use it outside.