To activate your LED Christmas Tree Necklace, remove pull tab and press button on pendant for 3 light modes – fast flash, blink, and steady light. Breakaway lanyard makes this necklace super safe for all. LED Colors: 3 Jade Necklace Length: 28″ Pendant Dimensions (W x H): 1.75″ x 2.5″ LED Christmas Tree Necklaces come ready to use with 2 CR1220 Batteries.