The SVBONY 5x24 low power;wide angle telescope fixed to the body of a more powerful telescope and pointed in the same direction for initially locating an object to be observed. An adjustable focusing wheel is projected onto a non magnifying viewing window so you can aim the main telescope quickly and easily. High quality eyepieces and objectives. Quality crosshair viewfinder makes targeting celestial objects in your telescope easy! Fully coated, achromatic glass optics yield crisp, bright images for easy aiming. 4mm eyepiece offers high magnifications;look more closely and more detailed at the moon's surface and other planet; for viewing the moon and planets. Standard 1.25" 31.75mm fitting diameter, can be used in any astronomical telescope with a 1.25" focuser. Both ends have dust caps for protecting the eyepieces. The lens covers are interchangeable and easy to use and keep in a pocket. Specification: Focal length: 0.16 inch / 4mm Field of view: 62° fitting diameter: Standard 1.25” (31.75mm) Eye lens diameter: 0.39inch / 10mm Coating: Optical lenses Fully coated: High-definition structure of optical system: Aspheric Eyepiece Weight: 1.48oz / 0.09lb / 42g Element: 3 Element 2 Groups