Set The LightCap in the sun or hang it from a railing during the day and you'll have light all night long! The LightCap 300 is basically a solar powered water bottle with four white LEDs that will turn the bottle into a neat looking lantern at night. It features a waterproof solar panel, battery pack, and "will stay bright for hours while the rechargeable Ni-Cad batteries will last for at least 300 cycles" on a four hour charge in sunlight.
