An inner tube wrench, also known simply as a tube wrench or a spanner wrench, is a specialized tool used primarily for installing or removing valve stems from inner tubes, particularly in tires. It typically has a slim, elongated design with a small socket or clamp mechanism at one end that fits over the valve stem. This allows for tightening or loosening the valve stem without damaging it, which is crucial for maintaining the integrity of the inner tube and ensuring proper inflation of the tire.