Tipton combines the Best Bore Brushes and Ultra Jags into a convenient 26 piece set that covers most of your bore cleaning needs. The set includes jags and brushes for calibers .17 through .45 (.20 caliber jag and brush are not included) and all pieces have 8-32 threads except the .17 that has 5-40 threads. The box is hinged and has slots that are marked for specific calibers.