Internal stopends are used in conjunction with another gutter fitting to cap off the end of the gutter system at that fitting, usually a running outlet. The internal stop end is introduced into the fitting in exactly the same way as you would install a piece of gutter - the back edge of the stop end is installed first before gently pulling the front edge down and inside the clip of the fitting, compressing the stop end onto the rubber sealYou can compare both types of stopends, internal and external, in our short PBSL Group video below;