Economical and user-friendly container closure system for metal buckets. Innovative tension ring with safety pin enables easy and reliable usage and resealing. Manual or complex machine concepts are usually required to close metal buckets with resealable spring clamping rings. The development of this clamping ring, including safety pin, provides an economical and user-friendly closing system for metal buckets by a simple snap-on process to completely close the unit. It is very easy for the user to open and close the container again.