I'm not gonna lie, I'm very disappointed by this toy. I was interested in it due to the two knots and the size, but I can't even get it in me. The silicone is far too soft to insert, let alone ride, and when its attached to a vertical surface, its incredibly bent and floppy. The weight of it also unseals the suction cup after a while.
The size was great, and if the silicone was more firm, it would be great. But unfortunately, this isn't it. If you're ok with softer toys then it could be interesting to try, but you'll definitely need a partner to help insert and control it.