Double pole, Triple wire, Non-Fusible Mechanical Interlock Receptacle. 60 amp, 480 vac. 60A 2P 3W 480V MECHANICAL INTERLOCK Legrand-Pass & Seymour http://www.legrand.us/product-detail/PassAndSeymour/IEC-309-Products/Fusible-NonFusibleMechanicalInterlock/Non-Fusible-Mechanical-Interlock/60-Amp/PS3