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.
FloPlast Cast Iron Effect Half Round to Cast Iron Half Round Gutter Adaptor
FloPlast PVC Half Round to Cast Iron Half Round Gutter Adaptor - White
Cast Iron Half Round Gutter Union - 115mm Primed
Cast Iron Half Round Gutter Stopend Outlet - 125mm for 75mm Downpipe Primed
FloPlast PVC Square to Cast Iron Half Round Gutter Adaptor - Brown
Cast Iron Half Round Gutter Left Hand Angle - 135 Degree x 125mm Black