Prunus 31&rsquo;&rsquo; Targeting Practice Fiberglass Arrows with Adjustable Nocks and Fixed Tips in Green and White Plastic Vance 12 Pack Prunus 31 inch FIXED TIPS fiberglass arrows, durable for target practice. Nocks are tight while not glued, could be used for compound bow directly, please change the nock direction while using recurve bow or long bows Total length: 31, Vance length: 3 Weight: 36 g Outer Diameter: 7.8 mm Tips : 100 grain, Spine: 500 to 550, Suit for 18 to 40 pounds bow One dozen per carton, gently packed in white high density foam