A box-end wrench is a type of hand tool used for tightening or loosening nuts and bolts. It features a closed loop, or "box," at one end that fits over the fastener, providing a secure grip. This design allows for better torque application compared to open-end wrenches, making it ideal for working in tight spaces. Box-end wrenches come in various sizes and can be found in both metric and standard measurements. They are often part of a larger tool set, which may include other tools like open-end wrenches and ratchets. Many box-end wrenches also have a ratcheting mechanism for added convenience.