You are browsing through Zazzle's Challenges stickers section where you can find many styles of Challenges stickers available for customization or ready to buy as is. There is no minimum order size and you can order them in sheets. Many sticker designs can be customized with your own artwork and text. To see some of the other products available on zazzle.com, check out our main challenges page. Most round sticker orders ship in 24 hours.