Suction cup for Window

Hi All,

I am looking a suction cup. I am experimenting so do not need packs of 5, 10 or a 100, or pay silly delivery costs just need the one until I know it works for what I need. Suction cup must be a min of 50mm with a hole for a hook, something like the one in the picture. I do no actually need the hook either, just the hole to be present.

Anyone know if the mainstream stores stock anything like this please?


Thanks.