Aprilaire 4270 Pleat Spacer for Models 2400 and 5000 (6-Pack). Have you upgraded your Model 2400 not to use these spacers anymore? This component looks like a large comb. It is designed to support the filtering media for even loading of particulate throughout the Air Purifier media. This will ensure maximum life from it. There are six pleat spacers in every Model 2400 and 5000.