Cách sử dụng
A ferrule is a small metal or plastic ring or cap that is put around the end of something, like the end of a pencil or a stick, to make it stronger or to hold it in place. You might use a ferrule on the end of a walking stick to make it more durable, or on the end of a paintbrush to keep the bristles from fraying. Basically, a ferrule is a kind of protective covering that helps to reinforce or secure something.