Nightmare Xtreme Arrows 500 12 pk. 100 percent 24T carbon shaft construction;Shield-style fletching for improved flight stability;Shaft length: 32 inches;Inserts installed with additional loose inserts included;Compatible with compound, recurve, and traditional bows;300 spine 8.4 GPI 0.297 inch OD;350 spine 7.5 GPI 0.291 inch OD;400 spine 7 GPI 0.289 inch OD;500 spine 6.3 GPI 0.285 inch ODtable.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; } Item Category Code: 1000 Product Group Code: 1000A Product Sub Group 1: 1000A1 Product Sub Group 2: 1000A1B Inactive: No Pack Size: 12