Material: This 10-300-30mm monocular telescope is made of BAK4 optical prism material, high light transmittance, large field of view, bright and transparent, no dark edges. Portable and Convenient: It is 14cm long and can be easily grasped with one hand. It can also be put in your pocket. Very convenient to carry. It is an essential equipment for bird watching, wildlife, hunting, hiking, mountaineering, camping, surveillance and travel. Product details: large caliber, enough of light to see a wealth of detail; high-definition blue film used in the lens, clear image, eye-care; flexible and convenient free focus 10-300X ultra long visual distance; hanging eye mask, suitable for all kinds of crowd; with metal interface, can be connected to a tripod. Waterproof and anti-fog: Waterproof, anti-fog and anti-scratch glass coatings ensure use in the field. Contents: 1 monocular