A power cage, also commonly known as a power rack or squat cage, is a fundamental piece of strength training equipment. Here's a breakdown of its key features and purpose:

Purpose:
- Its primary function is to provide a safe and versatile environment for performing free-weight barbell exercises.
- It acts as a "mechanical spotter," allowing individuals to lift heavy weights without the risk of being trapped or injured.
Design:
- Typically consists of four vertical posts connected by horizontal bars, forming a sturdy cage-like structure.
- Features adjustable horizontal bar catches (also called safety pins or spotter arms) that can be positioned at various heights.
- Many power cages also include a pull-up bar, and some have attachments for cable systems or other accessories.
Benefits:
- Safety: The adjustable safety pins prevent the barbell from falling on the user, enabling them to push their limits safely.
- Versatility: Suitable for a wide range of exercises, including:
  - Squats
  - Bench presses
  - Overhead presses
  - Deadlifts (with modifications)
  - Pull-ups
- Progressive Overload: Allows for safe and effective progressive overload, which is essential for building strength and muscle.
Variations:
- There are full power cages and half racks. Half racks are open on one side.
- Also smith machine cages that combine a smith machine with a power cage.

In essence, a power cage is a cornerstone of any serious home or commercial gym, offering a secure and adaptable platform for a multitude of strength training exercises