These two products are corner castings installed on containers and twist locks for fixed containers. Container corner castings are installed on eight corners of the container to assist in fixing the upper and lower layers of containers. Container corners can also protect the container body. Twist lock ,a device used to secure a container.When using it, try to insert the twist lock into the bottom hole of the corner of the container, and then push the handle to lock the container. Shouguang Esen Wood (Accessories)Co.,Ltd have good quality and competitive prices parts.