Brass Pirate Monocular 25x30 Zoomable Vintage Adjustable Telescopic Monocular Optics Telescope Aluminum Alloy Copper for Navigation Sailing Voyage View Watching Games Big eyepiece antireflection coated blue film, the vision, viewing comfort Large objective lens to increase the amount of light, the image is more clear and bright All-optical glass lenses, all surfaces of the multilayer broadband coating Imaging does not cast no distortion, viewing pleasure Good to have when you travel or work on the sea or at open and wide surroundings, never miss any important or beautiful scenes