- 21inch laptop and phone screen amplifier. Dimensions: total length 19 in (50 cm), total height 14.3 in (36.5 cm). Screen area length 19.3 in (49 cm), height 10.5 in (26.7 cm). - Powerful compatibility: Uses HD zoom optical technology and can be applied as a screen magnifier for laptop, tablet, and mobile screens. - Protects your eye: High-definition optical technology enlarges phone content up to 3x, helping relieve discomfort and visual fatigue from long periods focusing on small screens. - High quality materials and design: The screen magnifying glass uses high-definition optical lens material and supports multiple viewing angles, enabling a 3D-like viewing experience away from the screen. - Practical use scenarios: watch videos on a phone more comfortably, read documents or eBooks on a larger display from a laptop or tablet, or follow recipes and instructions on a small screen during travel or in the kitchen.