I bought three suckers varying quality of this company. After delivery I have all attached to a vertical glass pane - no load. The two big sucker held easily and for more than one week. These little suckers (2 pieces) were in each case after a short time on the ground. This product has disappointed me and I can not recommend it. I'm simply not what it should: keep on a disk a long time. I would also lack the confidence to make a glass pane just raising short term.