Specially designed for users to use smartphone to control the font size and color of lines, also support speed adjustment and quick change of turning page. Comes with 8 adapter rings, fits any camera with lens diameter from 49mm to 77 mm. The lines of the mobile phone interface are reflected onto the transparent glass of the inscription device, so that the speaker can look at the camera and speak. The cap cover can prevent objects scratch the glass plate. Portable and lightweight, good accessory for interview, speech, TV show, etc.