AGPtek Steady On Mood Light Garden Deco LED Floating Round Ball, Great for Pool, Ponds & Parties -- 8cm/ 3inch (Cool White Color, 12 PCS) Floating led pool lights are waterproof plastic balls containing LED mood lights. simply throw them in water and it will light up autodidactically. Use a coin to twists off the bottom to replace battery,Please note the +/-polarity when you replace the battery. Power supply: 2 X CR2032 batteries(replaceable) Battery; Last time:30-70hours