You'll know your lighter needs refilling when it starts to produce a weaker flame or no flame at all despite being sparked. If you notice the flame height decreasing over time or if the lighter requires multiple attempts to ignite, it's likely running low on fuel. Additionally, some of our MK lighters have a fuel level window, allowing you to visually check the remaining fuel. If you're unsure, it's always safe to refill your lighter if you've been using it regularly and haven't refilled it in a while. Jump to see how to refill your MK Lighters