PREFA drain pipe 3m As with gutters, special accessories are used to install the downpipes. These are available as prefabricated parts in standard sizes - to match the respective downpipes. Gutter attachment sockets in slanted or straight designs are used to connect to the gutter. So-called water catcher or collection boxes are also common in various shapes. Depending on the projection of the eaves and roof overhang, downpipe bends are used individually or in combination, as well as conical slanted pipes to create a functional and as attractive as possible transition from the gutter to the downpipe. Pipe clamps are used to attach the downpipes to the building wall. The downpipes are prevented from slipping through the pipe clamps by half-bulges or noses. Changes in the direction of the downpipe, for example due to projections or recesses in the facade, can be bridged with a base elbow (stretched S-shaped transition piece). Ring-shaped standpipe caps are used for the professional standpipe connection. If rainwater is to be removed, a rainpipe flap is installed. Free-ending downpipes are finished with a pipe outlet with a slanted end piece or bend, which are provided with a bead at the end.