These inserts are engineered for crossbows shooting over 300 fps.
Hevi-Hit insert has MASS weight of 51 grains and over 80% more Weight Forward distribution, while standard insert has very little weight forward distribution.
Extra long knurled insert for better adhesion to carbon shaft interior wall. Contributes to optimal balance point for 20" shaft.
* Mass Weight - 51 grains each
* Diameter - 24/64" exposed end