The single flame and the double flame is part of Zippo’s new lighter insert collection. These durable lighter inserts offer an odourless heat source that lasts. Both are designed to fit all regular Zippo lighter cases (excepting the Slim, Armor or 1935 Replica cases). Use the push-button to ignite the insert and watch a nice blue flame emerge. The inserts produce that same click sound that you have come to love about Zippo lighters. Note: Inserts should be filled with Zippo butane fuel before use. Bonus items include six genuine Zippo flint dispensers to keep your lighter working at optimum performance, and one quality microfiber cleaning cloth to keep the lighter insert clean and shinning all the time.