Carbon Express X-Buster, Ultra Tuff Indoor Target Arrow Shaft (Designed for Indoor, 20 Yard/ 18 Meter Tournaments and 9.3mm FITA and NAA rules), 12-Pack TUFF LINE CUTTER- The X-Buster is heavier in grains per inch than CXL Pro arrows, and the additional weight eliminates the need for archers to "tune down" their equipment in order to obtain slower, more forgiving indoor speeds. ENGINEERED FOR DURABILITY - Ultra Tuff Construction for hard density indoor targets including stramit material. Diamond Coat Finish provides smoother draw and easier pulling from a target. REAL STRAIGHTNESS - Every Carbon Express X-Buster arrow is laser checked for straightness to a remarkable 1/10,000 of an inch. Maxima Pro Recurve RZ straightness of +/- 0.0025" is a maximum measurement, not an average. MATCHED SET - Carbon Express X-Buster 12 pack shafts are sorted and matched by weight and spine for best-in-class consistency. Spine selection sorting tolerance is +/- 0.002". Weight sorting tolerance is +/- 1.0 grains. ITEM SPECIFICATION: 600-Size, 9.0-GPI, 31" Length, 0.584-Inch spine, and 0.329-Inch diameter Bare shafts have a Diamond Coat finish and come with BullDog Nock Collars and Pin Nock Adapters Ultra tuff construction - for hard density indoor targets Bare shafts have a Diamond Coat finish and come with BullDog Nock Collars and Pin Nock Adapters Ultra tuff construction - for hard density indoor targets Weight tolerance: +/- 1.0 grains Spine selection tolerance: +/- 0.002"; Straightness: +/- 0.0025" Item specifications: 600-Size, 9.0-GPI, 0.584-inch Spine and 0.329-inch Diameter