These are super strong suction cups. They are great for working with glass but could also be useful around the house. The package says they can hold 28 lbs each and I believe it.

Just to show how strong they are here is my 4 year old daughter hanging from them while they are stuck to the fridge!

They have a handle/lever to attach them which locks with a little plastic clip to keep them in the attached position. Overall, they are really great suction cups.

They are available for $9.99 for a set of 2 on amazon here: http://amzn.to/1Qq0SJF

Full Disclosure: I received these at a discount in exchange for my honest review.