It does exactly what it says, however its only 7 stones weight saved. Most Quivers have a weight reduction of 30%. 500 arrows is 50 stones, and the quiver weights 8 stones. So the quiver reduces the weight to 35 stones, but with the quiver weight 8 stones. This puts the weight of quiver and arrows at 43 stones. In reality its more like saving you 14% weight than 30% do to the quiver weighting 8 stones.