SVBONY 1.25" fully coated wide angle 62°aspheric eyepiece is perfect for broad field lunar observations medium sized star clusters;cloudy nebulas and deep sky targets. New to star gazing and didn't know what you needed to satisfy your needs;here is something can help you make an educated decision:Make sure that you know your telescope;and how to calculate your optimal magnification for the objects you wish to view;the magnification equation:Magnification=objective focal length/eyepiece focal length.Typically;you do not want to exceed 50x per inch of the telescopes or the images will be blurry;for example;you have an 8" lens you get 8x50=400x. So research what the best magnification is for the objects you wish to view. Applaction: Watch the scenery;bright celestial observations;nebula;broad field lunar observations;medium sized star clusters;cloudy nebulas;deep sky targets;viewing the moon and planets. 62 degree apparent field of view: Ultral wide angle for maximum detail and definition across the entire field of view;gets a virtually distortion free image. Fully coated optical lenses: FMC glass optics increase light transmittance;enhance details on jupiter;saturn;Mars;venus and get high achromatic images. The structure of the optical system: Aspheric eyepiece designed primarily for planetary observation and perfect for deep sky objects. Standard 1.25" fitting diameter: Perfect for broad field lunar observations in any astronomical telescope with 1.25" focuser. 4/10/23mm focal length: Low;medium and high powered magnification for lunar observation holes;more closely and more detailed at the moon's surface and other planet.Pay attention:Don't look directly into the sun;otherwise it will burn the eyes. Package include: 1xSVBONY 4mm 10mm 23mm aspheric eyepiece