Draw the Box zone to cover the area of the intersection where you want extensions for greens and/or all reds. Note that pedestrians and/or other vulnerable road users (VRUs) can often trigger the Bike Extension Outputs in the box, so you may want to leave a gap between the edge of the Box and any pedestrian crosswalks. Configure the Box outputs, Bike and/or Vehicle, that you want to use as controller inputs to trigger extensions.