1. High -using industrial- aluminum and advanced optical lens design to capture photos and videos with and .2. Dual split-screen lens mirror video effect-when the teacher puts his hands , participants will be to see a complete of the piano keyboard, and participants can still see each finger on the note at range through the mirror video. Students, students/participants The reader sees it in the expected way.3. Universal design-the lens is suitable for mobile phones with a camera lens diameter of no more than 13mm, such as for , , and other smart phones or even computers.4. Wide- hemisphere --The wide- lens projects a super range, you can see the full-key bracket without standing, with higher definition, and can be greatly expanded to 180 field of , such as crowds, buildings and landscapes.5. Portable and detachable-easy to carry when traveling and hiking. The lens is easily fixed to your phone with a soft rubber clip that will not scratch or damage your mobile device. Improved the length of the clip to more stable on the phone.Product name: Piano Sparring LensFeatures: dual-screen, full-key, distortion-free piano online teaching lens, art online teaching fisheye lens, painting online teaching super wide- lensAdvantages: more high-definition, larger , no need for brackets to see the full keyMaterial:ABS+metalcolour:BlackPackage Contents:1 x Piano sparring fisheye lensOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.