62 degree wide angle for maximum detail and definition across the entire field of view;gets a virtually distortion free image. Suitable for lunar observation holes;look more closely detailed at the moon's surface and other planet;perfect for viewing the planets, nebula, astronomical wonders, birdwatching, scenery,concerts. Standard 1.25" fitting diameter. Fits for any astronomical telescope with standard 1.25" focuser;perfect for broad field lunar observations. Both ends have dust caps for protecting the eyepieces.The lens covers are interchangeable and easy to use and keep in a pocket. SV221 diagonal mirror reflects the telescope's light path 45 degree to provide a more comfortable viewing angle, suitable for observing objects overhead. Correct upside down and left right reversed image, the view image is upright. SV221 diagonal mirror interface is 1.25” and the thread size is 28.5*0.6, to connect to astronomical telescope with 1.25” interface and 1.25” filter, for a better observation experience.Standard 1.25 inches diameter can be used with 1.25 inches telescope accessories such as eyepieces and filters. SV221 diagonal mirror have brass compression ring design, provides a uniform pressure receiving area when holding the eyepiece, fingertip screw clamps accessories effortless fixes more firmly and will not damage your eyepieces.