Gable extension from the Swedish brand String. If you're looking for a way to upgrade your String shelving system, the brand's end extension is a great choice. Not only are these gable extensions easy to install - simply attach them to the bottom of your floor gable - but they're also available in black or white to perfectly match your installation. With the end extensions from String, you can easily adjust the height of your shelves without having to replace the entire set. This is a quick and efficient way to upgrade your String furniture.