A power rack (also known as a power cage, squat cage or squat rack) is a piece of weight training equipment that functions as a mechanical spotter for free weight barbell exercises without the movement restrictions imposed by equipment,Its general design is four upright posts with two adjustable horizontal bar catches (also called “supports,” “rails” or “pins”) on each side. Many power racks also have accessory attachments, such as a chin-up bar, pulldown cable attachment, or pegs for storing weight plates.