How to use Niu Wangmo chair?

There are many ways to use it. I said two kinds. The woman knelt on the stool, her head stuck in the empty place of the back of the chair, and her feet fell with chains. There are also men kneeling on stools and going to the back of the chair, while women stick their heads behind their backs and come in for oral sex. There are many men and women standing up to be pigs.