10-300x 40 Telescopic High - Power Binoculars 10x-300x magnification adjustable, 40mm exit pupil distance, large field of view, wide-angle eyepiece, can be connected to a cell phone, comfortable and portable.Product Size Monocular fully retracted length of 5.1 inches, fully extended length is 7.9in, big lens: and 1.37in diameter. small lens: and 1.3in diameter. see product size drawing for details.High Quality Material The smartphone monocular telescope is made of high quality metal barrel and metal case, sturdy and durable. FMC multi-layer coating, high light transmission, clear and bright imaging, restore the true color.Waterproof and Moisture-Proof The highly airtight fuselage makes it resistant to bad weather and adaptable to a variety of environments, and you can safely use it in rainy and wet conditions.Wide Range of USES Monocular for hiking, birding, mountaineering, concerts, Tours, ball games, and scenic views. It can be used by adults and children.