Light Up Halloween with our Happy Halloween green circle shape Our circle badges are about 3" in diameter. Squeezing our green Happy Halloween glow square breaks an inner ampule allowing 2 chemicals to mix together and create a bright greenish glow. Have a child-safe Halloween when you light your trick or treaters with our bright yellow glow shape. Each imprinted glow badge has a self-adhesive backing allowing it to stick on almost anything. Priced by the individual piece. Please order in increments of 1 piece.