External Stopends are used to cap off the gutter at the end of the run. They are called external because they fit over the outside of the gutter profile.They are fixed to the gutter by clipping the back end into place first, then pulling the gutter gently down inside the front clip. This exerts an even pressure on the rubber seal to make a waterproof joint.To prevent the end of the gutter from sagging down you should always support a stopend by fixing a fascia bracket within 150mm of the stop end.We recommend the use of SL40 silicon spray on all seals when installing our XtraFlo Industrial gutter.