MP3 SUNGLASSES with FM Radio 2GB MP3/FM Sunglasses, Absolute music freedom with no wires or cords to dangle or tangle. Up to 6 hours of playback time on a single charge (Built-in Lithium Ion Polymer Rechargeable Battery The high quality speakers with three directions of movement for precise positioning Flip-up lenses with contours that maximize protection against sun, wind and side impact. Polarized lens material to filter out 100% of all UVA, UVB, UVC and harmful blue light.