An A-frame is furniture used in BDSM scenes. It works similarly to a whipping post and a St. Andrew's cross. It is made up of a triangular frame that's around 7 feet tall. It is somewhat concave, such that there is space within the triangle. This is where a person is positioned for bondage and domination. Usually, a submissive's wrists are immobilized through rope or chain bondage. Their ankles may also be secured to increase vulnerability and humiliation.