Head Magnifier Rechargeable Magnifying Glasses LED with 4pcs Eyeglass for Reading Repair Item Type: Head Magnifier Product Model: MG81000GC Product Material: ABS plastic, 6pcs acrylic optical lenses. Lens Magnification: Front Main Lens: 1.5X Interchangeable Rear Secondary Lenses: 2.0X, 2.5X, 3.0X, 3.5X Small Secondary Lens: 8X Lens Focal Length: Approx. 38 ~ 330mm / 1.5 ~ 12.99in, please refer to the user manual for the focal length of each lens. Power Supply Model: USB charging type. Supports continuous operation for 5 hours with soft light, and 2.5 hours with strong light. Lighting Source: 3 x white LED light. Battery: 1 x 602030 polymer lithium battery with 300mAh capacity, shipped with built in battery.