Altra Arrows Micro Insert Weight 20 grains Silver. O.C. and improve down range accuracy. The micro insert weights are designed for use with all Altra 166 arrows and are stackable for infinite weight adjustment. Specifications for Altra Arrows Micro Insert Weight: Manufacturer: Altra Arrows Color: Silver Features of Altra Arrows Micro Insert Weight: Comes in 12 pk QTY Available 10 & 20 Grains Blue Loctite recommended for assembly Package Contents: Altra Arrows Micro Insert Weight Altra Arrows AA-AC-00009: Micro Insert Weight 20 grains Silver