The GPO SPECTRA™ 5x 3-15x56i (G4i Fiber) is a second focal plane hunting riflescope engineered for low-light visibility and medium-to-long-range shooting. Built around a 30 mm main tube and a large 56 mm objective lens, it delivers approximately 90% daylight light transmission to maximize target identification at dawn, dusk, or under spotlights. The illuminated G4i reticle utilizes a fine fiber-optic microdot powered by a CR2032 battery and managed by GPO's iControl™ system, which automatically turns off the illumination when the rifle is tilted or rested vertically to conserve power.

Key Features

• Optical System: Features a 5x zoom factor spanning 3x to 15x magnification with a 56 mm objective lens and an eye relief of 95 mm.
• G4i Fiber Reticle: Second focal plane reticle with an ultra-fine, daylight-bright fiber-optic illuminated center dot.
• iControl™ Illumination: Integrated angle-sensing power management automatically puts the reticle into sleep mode when not in a standard firing position.
• Turrets & Parallax: Capped hunting turrets providing 0.1 MRAD (1 cm at 100 m) click adjustments across a 250 cm total adjustment range, paired with a side focus parallax adjustable from 10 m to infinity.
• Durability: Nitrogen-purged waterproof and fogproof housing rated to withstand standard high-shock centrefire magnum recoil.

Specifications

• Magnification: 3x – 15x
• Objective Lens Diameter: 56 mm
• Main Tube Diameter: 30 mm
• Focal Plane: Second Focal Plane (SFP)
• Field of View at 100 m: 11.1 m (at 3x) to 2.3 m (at 15x)
• Exit Pupil: 9.5 mm to 3.7 mm
• Eye Relief: 95 mm
• Adjustment Click Value: 0.1 MRAD (1 cm at 100 m)
• Total Elevation/Windage Range: 250 cm at 100 m (25 MRAD)
• Parallax Adjustment: 10 m to infinity (∞)
• Power Source: 1x CR2032 3V coin cell
• Length: 370 mm
• Weight: 830 g

Who is the GPO Spectra 5x 3-15x56i for?

• Dusk and dawn deer stalkers — relies on the light gathering of the 56 mm objective lens and 3x – 15x zoom magnification to identify targets and place shots in low ambient light across open paddocks and varied terrain.
• Nocturnal vermin control shooters — utilizes the 0.1 MRAD click adjustments and fine G4i fiber reticle for precise shot placement on feral pigs and foxes at night without obscuring small target areas.
• Night vision and thermal clip-on users — benefits from the side parallax focusing down to 10 m, ensuring optical clarity and alignment when mounting front clip-on systems to this second focal plane riflescope.

Less suitable for: Weight-sensitive alpine or backpack hunters seeking an optic under 830 g (who are better served by a compact 1-inch tube riflescope with a 42 mm or 44 mm objective), or dedicated PRS competitors requiring first-focal-plane reticles and high-exposed tactical turrets.