2 1/2" - Unify the members of your campaign with this fun blinking round celluloid button. This button is offered in several stock shapes with custom artwork to suit your campaign message. Great for more than just political campaigns, this is also perfect for any ad campaigns such as beverage industry promos. Your custom 4/C art is included. It has a metal back, pin back attachment, one red LED, and batteries. Add some to your advertising efforts today!