* Small and cylindrical: They're generally small, typically less than an inch in diameter and a couple of inches long.
* Metal: Usually made of metal, often steel or aluminum, though sometimes with a plastic cap.
* Hexagonal or square head: The top usually has a hexagonal (six-sided) or square head to allow for wrenching. This is how you remove it to access the brake system.
* May have markings: Some brake plugs might have markings indicating their function or the type of fluid they contain. This is less common than the other features.
* Sometimes a protective cap: Some might have a plastic or rubber cap or boot to protect the threads and seal from dirt and moisture. This cap is often removed before unscrewing the plug.
In short, imagine a small metal bolt with a hexagonal or square head – that's a good general visualization of a brake plug. If you're unsure about a specific plug, it's best to consult a repair manual for your vehicle.
