Bohning's Screw-in Concave Points are designed for 3D archery. Its aerospace-inspired contours reduce the occurrence of bent points. These field points are sized in 1/64" increments to ensure a flush fit with the shaft. 17/64" points typically fit weaker spined small (.204 ID) shafts 9/32" points typically fit stiffer spined small (.204 ID) shafts 19/64" points typically fit standard carbon (.246 ID) shafts used for hunting 5/16" points typically fit stiffer spined standard carbon (.246 ID) shafts 21/64" points typically fit large aluminum 21 series with inserts 11/32" points typically fit crossbow bolts Outfit your premium bow set-up with Bohning's Premium Field Points! Each Premium Point is machined to the precise standards youve come to expect from Bohning. They're guaranteed to weigh within 0.25 grains of the specified weight and to be concentric (round) within 0.001" (.025mm). Premium Points are made from stainless steel for a durable rust-free finish. The end result is an arrow that spins true and flies clean and stable time after time. Tech tip: to help prevent points from loosening, apply a small amount of Bohning's Tex-Tite or Seal-Tite Wax to point threads. Proudly manufactured at the Bohning Factory in Lake City, Michigan, United States.