The Ravin R339 (often listed as RAVIN R339 or SKU 815942023396) is a 3-pack of high-performance crossbow arrows designed specifically for Ravin crossbows. Weight: 400 grains. Straightness Tolerance: .001 inches. Quantity: 3 arrows per pack. Vanes: 2-inch high-performance vanes. Compatibility: Engineered for Ravin Crossbows, which utilize Helicoil technology. Usage: Designed for, but not limited to, big game hunting (deer, elk, bear) and high-speed target shooting.