Each Disc has 4 Ultra-Bright LEDsBrightest Light Up Disc AvailableStandard Size, 175 GramsSoft and Comfortable FeelEasy to Use OnOff Button The GoSports LED Disc is the brightest LED disc available. Other companies use just 1 LED, but we use 4. The 4 LEDs make sure you can see the disc during dusk hours unlike the other discs that dont start showing up until it is pitch black. Each disc includes 2 CR 2032 (3 volt) batteries that will power the disc for well over 12 hours of continuous use. The disc is standard size (10.5), weighs 175 grams and flies like any normal disc. The disc can be used like any regular disc during the day and then just push the button to power on the LEDs and continue having fun into the night. The disc is water resistant, but we do not recommend prolonged exposure to water.