12Pcs 20" Crossbow Bolts Fiberglass Arrows Flat Nocks 8mm Shaft Diameter: 8mm. For draw weight 30-60 pounds bows. Matched with replacement screw tips for optimal accuracy and target penetration. Archery hunting arrows with strong, lightweight fiberglass shafts and improved thickness for durability. Colored plastic fleches permanent nickel-plated stainless steel tip perfect for target practice and outdoor shooting. Fixed flat nocks are perfect for your crossbow compound & recuve bow. Good performance, low hand shock with good speed.