Our disk is a 90 cell plastic disk with a mechanical knock-out wheel. The disk uses vacuum to suck the seed to it, then it rotates and drops the seed down a seed tube into the ground. The knock-out wheel rolls on the suction side of the disk to poke out any stuck canola seeds or debris that may get caught in the holes. It’s similar to John Deere’s sugar beet or sorghum disk and knock-out. Since our disk has 90 cells on it, it turns much slower than the John Deere sugar beet or sorghum disks which only have 45 cells. With the high seeding rates of canola, this allows to keep tractor ground speed up from John Deere’s recommended speed of 3 mph to 5 mph.