The KT-MP200, KT-MP300, KT-MP400 and KT-MP500 mounting plates are for use with the KT-CAB3000LDR and KT-CAB4000LDR Cabinets. To install Kantech KT300, KT-400 and KT-NCC controllers, KT-MOD-REL8 relay modules, KT-MODINP16 input modules and KT-MOD-OUT16 output modules, one of these plates is required.