The Monstrum Tactical S330P is a compact, heavy duty prism scope with a fixed 3x magnification and a 30mm objective lens. Ideal for rapid close to mid-range target acquisition out to 300 yards. This scope uses a glass prism optical system rather than a refracting lens system like traditional scopes, allowing for better optical quality in a much smaller package. The crystal clear optics give a comfortable eye relief of 3.0-3.5 inches. The reticle can illuminate in red or green with multiple brightness levels or viewed in black when off to cover most lighting environments.