The bdx sierra3 riflescope provides the hunter an illuminated auto-holdover dot on targets.It features exceptional spectracoat lenses levelplex digital anti-cant and kinethic kinetic energy transfer indicator.The onboard applied ballistics ultralite calculator sends ballistic drop data via bluetooth directly to the sierra3bdx's bdx-r1 reticle providing an illuminated holdover dot and wind hold.Download the free bdx app for ios or android to setup ballistic profiles.This model has a 3.5-10x magnification with a 42mm objective and black finish.Adj Size: .25 MOAMagnification: 3.5-10xObjective: 42mmField Of View: 27.80-9.40 ft @ 100 ydsEye Relief: 4.20"-3.46"Tube Diameter: 30mmLength: 12.75"Weight: 20.90 ozReticle: Illuminated BDX-R1 (5)Parallax Adjustment: 100 ydsParallax Adjustment: 100 ydsProofs: WaterproofCoating Type: SpectraCoatOptic Coating: SpectraCoatOptic Coating: Spectracoat