To activate your LED Bead Necklace press the button on the battery pack. With each push of the button set the bright LEDs to 2 different flash sequences or a calming still light. Dimensions: 31 in. long LED Colors: 6 Green Light Up Beads Flashing Mardi Gras Necklaces include 3 replaceable CR1220 Batteries. Flashing Mardi Gras Beaded Necklace Flashing Body Light Lapel Pins by Blinkee All Products LED Jewelry Light Up Necklaces Mardi Gras Rainbow Multicolor