Incredibly tough tempered metal alloy manufacturing proves to outlast and endure in the field against the elements and debris. Rugged nitrogen filled and shock proof body enhances scope vitality. Triple illuminated reticle color type feature allows a red, green or blue visual hue to choose from and promotes optical ease during any scenario. Green optical coating adds ease in visual alignment between operator and target. Adjustable picatinny rail adapter system easily fits 20mm rails making this one versatile scope. Tube diameter measures out to 25.4 mm and eye relief range of 69.1-85.09 mm. Metal frame scope magnifies from 3x-12x.Specifications: Construction MetalLength 14.5 inches.Weight 1.3 lbsIllumination Red/Green/BlueObjective Diameter 40 mmEye Relief 69.1-85.09 mmTube Diameter 25.4 mmField of View 13.40-40.38 @ 100ydsReticle Mil-DotOptical Coating GreenShock Proof YesOne Piece Tube YesF.O.V. Adjustable YesNitrogen Filled YesWater proof YesFog proof Yes 1X Scope