A knotted dildo you can ride or plug in, and the devilish design earns its name. A wicked curve works your prostate the whole way down — then you reach the ledge and the real work starts. Grind over it and the knot doesn't just stretch your first ring, it drives the head straight through your second, both at once, locked around the neck. Turn it around and the curve hits somewhere new. Choose your starting size, then work your way up the range.