A. Ease of Use These stickers can be applied to mobile phones, laptops, tablets, personal computers, TVs, and other small electronic devices. Simply stick the sticker on the back of your mobile phone or the surface of the electronic device. B. Effectiveness Each sticker can effectively protect against electromagnetic frequencies (EMF) and electromagnetic radiation (EMR) generated by mobile phones, laptops, tablets, personal computers, TVs, and other small electronic devices. C. Working Principle Ordinary electronic devices usually emit electromagnetic frequencies (EMF) and electromagnetic radiation (EMR), which may be harmful to the human body. The mobile phone protection sticker uses magnetic negative ion technology to absorb and neutralize the ions in electromagnetic frequencies and electromagnetic radiation. D. Lightweight and Thin Size The lightweight and thin design does not add much weight to your mobile phone. The thin design allows you to stick it on your mobile phone or any other electronic device, making it convenient to carry and providing radiation protection. E. Product Type Electromagnetic protection sticker F. Color Silver G. Material Silicone H. Size 28 mm in diameter I. Package Contents 20 stickers Only the above - mentioned items are included in the package, and other items are not included. J. Precautions Light and different displays may cause slight differences between the color of the item in the picture and the actual product. The allowable measurement error is ±1 - 3 cm.