4mm micro-diameter uniform ACU-Carbon fiber construction Pre-installed 4mm Microlite nocks (6 gr) Straightness: +/- .001" Uses 5/16" diameter field point Compatible with Easton 4MM Titanium Half-Out #207080 & 8/32 Easton 4MM Half-Outs #2070887 Includes 8/32 Easton 4MM Half-Out (Aluminum) inserts for optimum FOC Spine Size (Weight): 250 spine (9.8 gpi) 300 spine (9.3 gpi) 340 spine (8.3 gpi) 400 spine (7.4 gpi) Included Half-Out Specifications: Precise two-point interface with shaft increases