Material:Plastic Feature:1.It can relax muscle ache and improve blood circulation. 2.Small enough to fit into a bag,you can take it anywhere with you! 3.You can use it to areas in need, including the neck, base of your skull and shoulders. 4.Powered by 3 AAA Batteries,Batteries exclude Design:They Have packed into one paper box,so we can't open the box and check the exact color before we post,u may received all one same color or mixed color,pls note that before u buy,thanks Color:May vary to the stock,customer may not choose Size:8x9cm