Portable Apron Feeders Portable KPI-JCI Apron  Feeders are available in sizes ranging from 3 1/2 x 30 to 4 x 50 in two and three chain configurations.  Perfect for large mobile crushing applications, these units excel at handling tough and sticky material.  Durability is a given with features like impact protection offered by the idler rollers, and segmented sprockets ensure maximum uptime in addition to ease of maintenance.