Steambow FENRIS Arrows Set of 5 Black. 006 at 20 with a 300 spine. The arrows also come equipped with nocks developed specifically for the FENRIS and 125-grain tips. Specifications for Steambow FENRIS Arrows Set of 5: Manufacturer: Steambow Color: Gray Fabric/Material: Carbon Quantity: 5 Spine: 300 Straightness: 0.006 in Package Contents: Steambow FENRIS Arrows Set of 5 Steambow 307: FENRIS Arrows Set of 5 Black