To be able to use this you need a completely flat large soft surface... otherwise it will not hold.

As long as the surface is clean enough to get a good initial suction you don't have to worry about this thing going anywhere.

Some reviews seem to mention problems with sticking to non-smooth surfaces, which I can believe since suctions cups are made to stick to smooth surfaces only.

You must have a clean flay surface to use this, but if you do it is fantastic.

Holds tight on any flat smooth surface

This probably goes without saying, but you don't want to use this suction cup on an uneven surface.

Wish the suction cup was stickier like a cheaper product I had previously used (that part of it broke...), but the description does say it needs to be used on smooth surfaces.

Finally a suction cup that works as it should

Solid as

Really satisfied ..works as it supposed to and great Product