A standoff is a threaded separator of defined length used to raise one assembly above another. They are usually round or hex (for wrench tightening), often made of aluminum, brass, steel or nylon, and come in male-female or female-female forms. In electronics they are frequently used to raise a printed-circuit board above a surface. When used to fasten cable connectors (i.e. "D" connectors) together, they are called "jack screws".