Introduction
Thank you for choosing the FULLJA 20x50 High-Power Binoculars. Designed for exceptional clarity and durability, these binoculars are perfect for a wide range of outdoor activities, including bird watching, hunting, stargazing, travel, and sports events. This manual provides detailed instructions on how to set up, operate, maintain, and troubleshoot your binoculars to ensure optimal performance and longevity.

Image: The FULLJA 20x50 High-Power Binoculars, showcasing their robust design and green-coated objective lenses.
Product Components
Familiarize yourself with the various parts of your FULLJA binoculars for proper handling and operation.

Image: A detailed diagram illustrating the key components of the binoculars, including the Ocular Lens, Eyepiece Cover, Right Diopter Ring, Central Focus Wheel, Anti-Slip Grip, Objective Lens Cover, Objective Lens, and Tripod Interface.
- Ocular Lens: The lens you look through.
- Eyepiece Cover: Protects the ocular lenses when not in use.
- Right Diopter Ring: Used to adjust focus for individual eye differences.
- Central Focus Wheel: Main adjustment for focusing both barrels simultaneously.
- Anti-Slip Grip: Textured surface for secure handling.
- Objective Lens Cover: Protects the large front lenses.
- Objective Lens: The large front lenses that gather light.
- Tripod Interface: Threaded port for mounting the binoculars on a tripod (adapter sold separately).
Setup and First Use
Follow these steps to properly set up and focus your binoculars for a clear viewing experience.

Image: A visual guide demonstrating the four steps to properly focus the binoculars, showing the adjustment of the central focus wheel and the right diopter ring.
- Adjust Interpupillary Distance: Hold the binoculars with both hands and bend the body until the two fields of view merge into a single circle. This adjusts the distance between the eyepieces to match your eyes.
- Focus the Left Eye: Close your right eye. Look through the left eyepiece and rotate the Central Focus Wheel until the image is sharp and clear.
- Focus the Right Eye: Close your left eye. Look through the right eyepiece and rotate the Right Diopter Ring (located on the right eyepiece) until the image is sharp and clear.
- Fine-Tune Focus: With both eyes open, use only the Central Focus Wheel to adjust the focus for different distances. The diopter setting should only need to be adjusted if your vision changes significantly.
If you wear glasses, you can adapt the binoculars by pulling off the rubber eyecups to get closer to the lens for a better view.
Operating Instructions
Your FULLJA 20x50 binoculars are versatile and suitable for various applications.

Image: Collage showing various activities where the binoculars can be used, including bird watching, hunting, travel, concerts, and sports.
- Bird Watching: Use the wide field of view to track birds in flight or observe them in their natural habitat.
- Hunting: Spot distant game with clarity and precision.
- Hiking & Travel: Enhance your sightseeing experience by bringing distant landscapes and wildlife into sharp focus.
- Concerts & Sports Events: Get a closer view of the action from the stands.
- Stargazing: Observe celestial bodies with enhanced brightness and detail, especially in low-light conditions.
Key Features
The FULLJA 20x50 binoculars are engineered with advanced features for superior performance.
- Professional 20x50 High Power: Offers powerful magnification and a large objective lens for bright, clear images.
- BaK-4 Prisms & Fully Multi-Coated Lenses: Ensures superior light transmission and brightness, resulting in sharp, high-contrast images with true color fidelity.
- 22mm Large Eyepiece: Provides a wide field of view, making it easier to locate and track subjects.
- Durable, Waterproof & Fog-proof: Constructed with a non-slip armor surface for excellent grip and shock resistance. O-ring sealed optics with a fog-proof coating prevent moisture, dust, and debris from entering, making them ideal for outdoor use in various weather conditions.

Image: A comparison showing the clear and sharp image produced by BAK4 prisms versus the dark and blurry image from normal prisms.

Image: Illustration demonstrating the wider field of view provided by the 22mm large eyepiece compared to smaller eyepieces.

Image: The binoculars shown in a rainy environment, highlighting their waterproof and fog-proof capabilities.
Maintenance and Care
Proper care will extend the life and performance of your binoculars.
- Cleaning Lenses: Use the included cleaning cloth or a soft, lint-free cloth. For stubborn spots, use a small amount of lens cleaning fluid applied to the cloth, not directly to the lens.
- Cleaning Body: Wipe the body with a soft, damp cloth. Avoid harsh chemicals.
- Storage: Store the binoculars in their carrying bag in a cool, dry place when not in use. Avoid extreme temperatures and high humidity.
- Protection: Always use the lens covers and eyepiece cover to protect the optics from dust and scratches.
Troubleshooting
If you encounter any issues, refer to the following common problems and solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| Image is blurry or out of focus. | Improper focusing; diopter not adjusted. | Follow the "Setup and First Use" instructions to adjust the central focus wheel and right diopter ring. |
| Two overlapping images or partial view. | Interpupillary distance not set correctly. | Adjust the hinge of the binoculars until the two fields of view merge into a single circle. |
| Fogging inside lenses. | Rapid temperature change; seal compromised. | Allow binoculars to acclimate to temperature. If persistent, contact customer support. |
| Difficulty turning focus wheel or diopter. | Dirt or debris; cold temperatures. | Clean the area around the wheel. In very cold conditions, movement might be stiffer. |
Specifications
Detailed technical specifications for your FULLJA 20x50 Binoculars.
| Feature | Specification |
|---|---|
| Model Number | B16 |
| Magnification Maximum | 20.00x |
| Objective Lens Diameter | 50 Millimeters |
| Special Feature | Waterproof |
| Product Dimensions | 8.27 x 8.23 x 0.04 inches |
| Item Weight | 2.38 pounds |
| Manufacturer | FULLJA |
| Date First Available | August 30, 2021 |
Warranty and Support
FULLJA stands behind the quality of its products.
- One Year Warranty: This product comes with a 1-YEAR warranty from the date of purchase.
- 30-Day Money-Back Guarantee: FULLJA offers a 30-day full money-back guarantee.
- Customer Service: For any questions, concerns, or warranty claims, please contact our professional service team. We are committed to providing the best possible service within 24 hours.
Please retain your proof of purchase for warranty purposes.