The JLB-03 is the smallest of the two leader boards and it measures 5 ¾ X 8 making it work well with smaller hooks and jigs and pre-tied leaders and it also allows you to pre load your tackle and be organized when you hit the water. When used with a Plano 2-3715 you'll have a little extra room for your leader spool, swivels, and scissors or whatever you choose. Leader board fits perfectly into the Plano 2-3715 box.