# Box Selection
Making your own extension is a powerful feature of the viewer. In this example we've made a box selection feature by implementing our own extension.
You can run the example live here (opens new window) or
Speckle Docs Speckle Docs Making your own extension is a powerful feature of the viewer. In this example we've made a box selection feature by implementing our own extension.
You can run the example live here (opens new window) or