The Kadee #147 HO Magne-Matic Coupler set includes two pairs of all-metal, self-centering Whisker couplers with medium 9/32" underset shanks. Designed for reliable performance, each coupler features a metal Whisker centering spring and comes with insulated #242 draft gear boxes and lids. These couplers can be mounted using the included gear boxes or in manufacturer-provided pockets, but should not be installed directly on metal surfaces to prevent electrical shorts. Ideal for modelers seeking durable, smooth-operating couplers for HO scale rolling stock.