Holiday Light-Up Necklaces. Wear this jolly jewelry throughout the winter season! Spark a new fashion trend with these holiday light-up necklaces. In stocking, Christmas tree and smiley-faced bulb designs, these pendants bring stylish cheer to every yuletide party! Each 2" plastic pendant is on a 30" beaded necklace. Batteries included. Our children’s necklace items contain breakaway features, attachments or materials required by the Consumer Product Safety Commission’s children’s jewelry standard.