Triple pole, Four wire, Fusible Mechanical Interlock Receptacle. 100 amp, 3/240 vac. 100A 3P4W 3PH 240VAC FUS MECH INT Legrand-Pass & Seymour http://www.legrand.us/product-detail/PassAndSeymour/IEC-309-Products/Fusible-NonFusibleMechanicalInterlock/Fusible-Mechanical-Interlock/100-Amp/PS4100FMIR9