Double Sided Suction Cup

I have a question about that particular item. I saw that the suction cup is 3" diameter... what does the base of the toy you stick to it have to look like for it to work? Does it pretty much have to be exactly the same size and shape as the suction cup for it to hold? Or could it be off a bit?

I'm hoping to find a suction cup that is compatible with the Boss by Tantus, and the normal Tantus suction cup won't work with it, because it doesn't have a hole in the base for it. So I'm wondering if maybe the double sided suction cup would work - but I know the base of the Boss isn't even close to the right size/shape to exactly match it, so I don't know if it would work together.

I'm not an official company representative, but I can give you my personal experience. We have the double-sided suction cup, and it definitely will work with pretty much any toy that has that circular base like most Tantus/Vixen/Sportshee ts/dildos-in-general have. However, I'm not sure it would work with the Boss. I think the testicles are actually too big on the Boss dildo, and since they would hang off of the suction cup, I think it might let air in, and the suction cup wouldn't work.

I just went and tried it with the only testicle dildo I own (Tantus Hank), and it works okay, but if it's jiggled around too much, it does release the suction.

The suction-cup would definitely work with circular bases or non-testicle dildos, but I'm not sure if it would hold The Boss dildo up well.