Specifications:

Magnification: 3-18x
Objective Lens Dia.:50mm
Tube Dia.:30mm
Adjustment Click Value: 1/10mil 
Reticle: mil 
Illumination: YES
Field of View: 36.67-6.1Feet @ 100 yards
Eye Relief: 100mm 
Exit Pupil: 16.2-2.7mm
Lens Coating: Fully multicoated
Parallax Setting: 100 yards
Finish: Matte
Distance between objective lens part and middle turret: 40mm
Distance between middle turret part to power ring: 32mm 
Diopter compensation from fast-focus eyepiece (+2 to -2.0)

Main Features:

30mm Monotube.
1/10 MIL windage and elevation adjustments for fine-tuning accuracy..
Turret lock sytem. Pull to adjust, press to lock.
Side Focus starts at 10 Yard.
Fast-focus Eyepiece for quick and easy reticle focusing
O-ring Sealed and Nitrogen Purged Ensure Water Resistance and Fog Proof performance; Shockproof to 750g. Waterproof at 1 m.
High quality 6061 T6 aircraft grade aluminum alloy with durable black matte finish.