SPROCKET / HUB 2 SIDE. Sprocket cast metal, square hole, 13T. .65" X .65"ID, 5.25"OD. Used on Planter Hopper Fertilizer 600 Series pull type. Casting number 319127 . 600 Series UNIT PLANTERS - HOPPER DRIVE, SHAFTS, SPROCKETS & MOUNTS 70319127: SPROCKET (13T)