The 8PCS Light up Scrunchies for Girls, Glow in the Dark Party Supplies, 3 Glow Mode Satin Scrunchies - are just as advertised.These are really nice quality. They are beautiful vibrant colored scrunchies even if you didn't turn on the lights. They are satin material and the elastic is very strong. You pull the plastic tab and turn it on. The three modes are slow flashing, fast flashing and solid. The batteries are not replaceable unless you cut the fabric, replace the batteries and sew or stitch it back together. I'm not sure what batteries these would have but I would guess LR44 since most of the light up items I have purchased use LR44 batteries.I have purchased light up scrunchies before and they last a long time if you don't have it on continuously for 24 hours. I have two that still work a year later. There are so many fun uses for this; birthday parties, festivals and even if you're walking at night for safety. Eight scrunchies that light up are a great value at $7.99 at the time of my order.I am attaching three photos. The first one shows you the white scrunchie and then the second photo is when I have the white scrunchie light set to solid. It has a multitude of colors and I love that it looks like a solid color until you turn it on, allowing you to wear it during the daytime and turn it on when you want to. The third photo is the assortment to show the material which is a soft shiny satin fabric.Overall a beautiful assortment of light up scrunchies - you will not be disappointed!