DiscoveryOpt VT-Z 4-16×42 SFIR Side Focus Scope

A 4-16× variable-magnification scope combining higher magnification, side-focus parallax adjustment and an illuminated reticle for precision-oriented recreational shooting.

Unlike an Adjustable Objective scope, Side Focus places the parallax control beside the turret assembly, allowing adjustment without reaching forward to the objective bell. This is particularly convenient when shooting from a supported position.

The combination of 4-16× magnification and adjustable parallax makes the VT-Z particularly attractive for PCP target shooting, grouping and zeroing where the shooter has a stable shooting position and wants more precise control over the sight picture.

Available specifications confirm a 42 mm objective, 25.4 mm tube, SFP reticle, red/green illumination, 1/4 MOA adjustment and side-focus parallax. 

Key Specifications

• Brand: DiscoveryOpt
• Model: VT-Z 4-16×42 SFIR
• Magnification: 4-16×
• Objective Lens: 42 mm
• Focal Plane: Second Focal Plane (SFP)
• Parallax Adjustment: Side Focus (SF)
• Parallax Range: Approximately 10 yards to infinity*
• Reticle Illumination: Red / Green
• Click Value: 1/4 MOA
• Tube Diameter: 25.4 mm / 1 inch
• Nitrogen Filled: Yes
• Lens Coating: Fully multi-coated
• Shockproof: Yes
• Waterproof: Yes
• Fogproof: Yes

ONE77 Scope Fit Guide

Recommended For: PCP air rifles and precision-oriented recreational airgun setups; spring-piston/gas-ram use should only be recommended after confirming suitability of the specific production version

Best Use: PCP precision shooting, benchrest, grouping, zeroing and target shooting at varying distances

Shooting Position: Excellent for benchrest and supported shooting; usable standing at lower magnification, although a lighter/lower-powered optic may be more comfortable for prolonged unsupported shooting

Magnification Advantage: 4-16× combines a usable lower end with considerably more target detail when the rifle is supported

Parallax Type: Side Focus — particularly convenient for shooters regularly changing target distance because the adjustment can be made without reaching to the front objective

ONE77 Note: The VT-Z 4-16×42 SFIR and MS 4-16×42 AOAC should not be treated as interchangeable simply because both are 4-16×42. Choose the MS where verified spring-airgun shock resistance is a major requirement. Choose the VT-Z where convenient Side Focus and illuminated-reticle functionality are the stronger priorities.

Mount Compatibility

Requires 25.4 mm / 1-inch scope rings.

Select the ring base according to the air rifle's rail system.

What's Included

DiscoveryOpt VT-Z 4-16×42 SFIR Scope

Accessories as supplied in the product packaging.

Some published versions include rings, side wheel, sunshade, lens caps and other accessories, but we should list those only after checking the contents of the actual ONE77 stock.

Please Note

Do not assume that “shockproof” automatically means suitable for every powerful spring-piston air rifle. ONE77 should recommend this model for springers only where the particular version's spring-airgun suitability has been verified.

Specifications and included accessories may vary between production versions.