The Thunder Bolts are made from the signature, Element Archery carbon weave technology used in the Rock shafts. This bolt has an ID of .300, comes with a 100 grain brass insert and is cut at 22 inches in length. This is great for the newer and faster crossbows with longer strokes. The carbon weave design gives this bolt amazing strength and consistency that is needed with today’s crossbows. You will be hard pressed to find a stronger and more accurate bolt in today’s market.