Toilet paper rolls are cylindrical tubes made of cardboard that serve as the core for rolls of toilet paper. They are typically about 4 inches long and 1.5 inches in diameter. Once the toilet paper is used, the roll is often discarded, as it is not recyclable due to its contamination with waste. These rolls are commonly found in bathrooms and are designed to hold sheets of toilet paper. The paper is unwound from the roll for personal hygiene after using the toilet. Many households use a holder to keep the roll in place, making it easy to access.