1 OUT 2: Piezo igniter can be used as 1 out 1 and 1 out 2. Ignition distance is 5-6mm. mounting hole is 18mm. PUSH BUTTON OPERATION: The Piezo Igniter requires no batteries, just push the button and a single click produces a spark. However, be sure to connect the notched wire or touch the mounting point. WIDE COMPATIBILITY: Works with all and gas gear. Some modifications may be required for installation and will not fit all existing mounting holes or cable lengths, please check before purchasing. MULTIPURPOSE: The piezo igniter is mainly used for lighting gas, stoves, ovens, heaters, fireplaces and so on. It can also be widely used for various outdoor activities, such as barbecue, camping and so on. SAFETY & RELIABILITY: The outer layer of the piezo igniter is made of plastic, which can effectively isolate the ignition and ensure safety at the same time.