MMF-302 6-zone interface modules provide an interface between the intelligent alarm system and a 2-wire conventional dtection zone. Click the link for more information: https://buildings.honeywell.com/us/en/products/by-category/fire-life-safety/control-panels/accessories-and-parts/monitors/mmf-302-six-zone-interface-module
MDF-300 dual monitor moduels are intended for use with addressable, 2-wire systems. They provide two independent 2-wire initiating device circuits (IDC) at two seperate consecutive addresses. Click the link for more information: https://buildings.honeywell.com/us/en/products/by-category/fire-life-safety/i-o-modules/monitor-modules/mdf-300-dual-monitor-module