The system incorporates long trench-like channels that are installed length-wise down the middle of existing taxiways and aprons (or built into new ones) and then covered with two steel plates, one on each side. There's a 1.5-inch (38-mm) gap between those plates, creating a slot which runs the entire length of each channel. That gap is covered with a split rubber gasket, in order to keep foreign objects from falling through.