This riflescope has main tube diameter 30mm and overall diameter of the objective bell is 44mm.

• 30mm Monotube, Ultra Short 270mm 10.3", 1/10MIL 1cm Adjust With Turret Lock System

• Fully Multi Coated, Side Focus Min @ 10 Yds, Long Eye Relief, Six Gear Red Illumination

• Center Dot Illuminated Etched Glass Reticle, w/ Honeycomb Sunshade, Flip Up Caps

• " A Must for Your Compact Air Guns and Light Weight Firearms, The Shortest Marksman Scope for You."

• Magnification: 4-16x
• Objective Lens Dia: 44mm
• Ocular Lens Dia: 33mm
• Ocular Lens Length: 35mm
• Exit Pupil: 11-2.75mm
• Optics Coating: Fully-multi coated
• Field of View: 26.2-6.55 feet@ 100 yds
• Field of View: 5.0-1.25°
• Eye Relief: 90-85mm (3.5-3.4")
• Length: 270mm / 10.5in
• Weight: 530g / 18.7oz
• Tube Dia: 30mm Monotube
• Click Value: 1/10MIL, 1cm
• Elevation Range: 17.5MIL
• Windage Range: 17.5MIL
• Parallax Adjustment: 10 Yards to infinite
• Reticle: Etched Glass MPR-V5
• Finish: Black Matte
• Illumination: Six gear
• Distance between objective lens part and middle turret: 40mm (1.6 inch)
• Length of middle turret part: 37mm (1.4 inch)
• Distance between middle turret part to power ring: 32mm (1.3 inch)
• Shock tested to 750g, water resistance IPX4
• Fully nitrogen purged to eliminate any fogging of the lenses internally
• Turret Lock System
• High quality 6061 T6 aircraft grade aluminum
• Focus mark: 10, 15, 25, 50, 100, 200 and infinite
• Diopter compensation from fast-focus eyepiece (+2 to -2)
• Including items: one pair of 30mm weaver scope rings, flip-up caps, honeycomb sunshade and cleaning cloth etc.