Ravin R18 Carbon Crossbow Bolt - 6 Pack - These R18 bolts provide a straight flying bolt that build confidence in your shooting abilities. 350 Grain Use In Ravin R18 Only 16in Length 100% Pure Carbon Construction Straightness Tolerance: .003 High-Impact Brass Threaded Inserts 2in High-profile Offset Vanes High-Impact Aluminum Nock Bushings Ravin-Engineered Polymer Nocks