A smooth, deep dildo with a dick head thicker than the shaft behind it — so every stroke makes you take that head again. It ploughs in, opens your first ring, then leaves you gaping around a shaft that suddenly feels easy. And that's only half of it. Keep sinking and the head goes hunting past your second ring while your lips get dragged back and forth over the fattest sexy part. Mount it to a machine or strap it on. Choose your starting size, then work your way up the range.