The YYJ-12 seed roller has twelve V-shapped holes, 1/8" (3mm) in diameter. Spacing is adjustable from 2-5” apart depending on seeder sprocket combination. Seeder rollers have cups/holes to cup the seeds to allow for singulation. Made from anti-abrasion plastic to prevent build-up of static electricity that causes seeds to stick together. Great for Arugula, Basil, Chia, Mustard, Turnips.