1, structural design: Zippo 1937 patent adopts foldable metal shell design, which makes the lighter more durable. In contrast, other lighters adopt different structural designs, such as plastic casing or fixed metal casing.
2. Flame adjustment: Zippo 1937 patent has an adjustable flame size design, and users can control the flame size by rotating the adjusting cover. This allows users to adjust the flame intensity according to their own needs to adapt to different usage scenarios. Other lighters do not have this function of adjusting the flame size.