The Ravin .003 R18 Arrows (6pack) are 350 Grain (with 100 Grain tip) and are intended to use with Ravin Crossbows Only. They feature 100% Pure Carbon Construction with a Straightness Tolerance .003 and High Impact Brass Threaded Inserts. These arrows also feature 2 offset vanes with High Impact aluminum nock bushings and Ravin Engineered polymer nocks.