Micro diameter hunting arrow; .166 Series - Micro Diameter Arrow - 100% carbon fiber construction micro diameter for maximum speed and penetration with less wind deflection; Spine Aligned - Every arrow digitally spine aligned for increased accuracy and shot to shot consistency; Matched Weight - Each dozen weight matched to +/-0.5 grains for precise shot consistency and tighter grouping; Ice Nano Ceramic Coating - Advanced nano ceramic arrow coating improves penetration and allows for easy removal from targets; Hand Fletched - Hand fletched for optimum vane adhesion and alignment; Shok Outsert Technology - 7075 hard anodized aluminum or 303 stainless steel outserts with standard 8/32 thread count and 5/16" diameter for maximum penetration