Sorry, but it feels necessary to point this out, because once it burns a butt hole-shaped hole in your brain, it seems only fair to share it with the rest of the world. It's called paying it forward.
This $15 "balloon knot" (shudder) keeps your real doll looking and feeling... er, real, I guess? It's such an odd accessory — it appears the sex doll folks are just looking to make a buck off of something you could make with some bubble gum and hairspray. Actually, maybe that's a real business idea?
Many sex dolls are masterful feats of special effects magic, and so perhaps this is just another add-on that might intrique many — kinda like how vibrators have fun and exciting attachments. Or maybe the non-functional "balloon knot" exemplifies why sex dolls like the "Real Doll" are so creepy to many — it's just there to make the sex doll appear more like the perfect human woman. The dolls aren't simply a sexual aide, or fun toy — they are often stand-ins for an idealized type of docile, compliant woman. Except that you have to literally remove a part of her to have sex.