Expose to light for a few minutes, turn off lights and watch them glow for about an hour. Glowing Imaginations glow in the dark stars make a great gift for the young or the young at heart. Recharge them as necessary and they will glow again and again. The Glowing Imaginations stars maintain light much longer compared to similar products on the market. Package size: 10" x 7". Largest stars measure 1.75" in diameter.