4K telephoto zoom monocular telescope 10300x40mm portable Waterproof and fog proof: The housing is sealed and nitrogenfilled to prevent internal fogging, allowing use in rainy days and humid environments without worry. and portable construction: Titanium alloy shell provides strength with low weight. The instrument weighs 1.1 pounds and retracts to 7.87 inches, so it easily fits in a backpack or bag during travel or camping. Optical performance: Equipped with a BAK4 prism and fully multicoated lenses. A larger objective lens allows more light to enter, delivering brighter, clearer, and sharper images with strong contrast and minimal obstruction. Telephoto zoom capability: 10300x40mm zoom range offers flexible magnification for distant subjects, suitable for a variety of viewing scenarios. Practical design notes: Compact and sturdy for rugged outdoor use, with dependable optics designed to maintain image quality in challenging weather conditions. Use scenarios: Birdwatching or wildlife observation in forests, wetlands, or coastal areas, especially when weather can change unexpectedly. Travel, camping, or hiking trips where a compact, capable optical instrument is desirable for distant scenery and landscapes. Outdoor sports events or concerts from stands or bleachers, providing longrange viewing without bulky equipment.