Specification: Frame material:pc Rechargeable way:USB rechargeable Battery style:50mA(3v) Width of the forehead frame :148mm/ 5.82" (approx.) Lens Height:44mm/ 1.73" (approx.) Lens Width : 66mm/ 2.59" (approx.) Leg Length :145mm/ 5.70" (approx.) Bridge :17mm/ 0.66" (approx.) Weight:40.0g Finding the focal length:Hold an object about 12-16 inches away from Led magnifying glasses,adjust until object is in focus. Note: Size for manual measurement, there may be a 0 to 1 cm error, belongs to the normal phenomenon. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!