Since the dawn of time (or so it seems) RV manufacturers have been using the versatile Jackknife Sofa in their interiors. Because of their versatility, a Jackknife is often used in places where a sofa makes sense, but in a pinch, you need to add sleeping. Great for those nights when you are “in the dog house” or the poker game goes late and your friend can’t drive home. The Jackknife, through the years, has become the go-to for adding additional or temporary sleeping arrangements.