Manufaturer Part Number: SOSBDX631The sierra6 family of riflescopes provides the hunter or marksmen with an intelligent auto-holdover specific to their ballistics, target, and environment.This model features sig's bdx ballistic data xchange technology.Adj Size: .25 MOAMagnification: 3-18xObjective: 44mmField Of View: 34.90-5.80 ft @ 100 ydsEye Relief: 3.90"-3.70"Tube Diameter: 44mmWeight: 23.80 ozReticle: Illuminated BDX-R2Parallax Adjustment: Side FocusProofs: Waterproof