What is a mechanical mod? A mechanical mod is an unregulated type of device. There is no circuitry in the mod to keep the voltage steady throughout the life of the battery. Since you are running directly off the battery you can't increase or decrease the voltage and the vape will slowly become weaker over the lifespan of the battery. However, there are no advanced electronics in mechanical mods which makes them extremely durable. They are ideal for those who want something that is dependable and won't break down. So when should you use them? If you're using rebuildable atomizers Mechanical mods are an excellent choice for those who choose to use rebuildable atomizers. When rebuilding, it's necessary to to fire the mod to see how the coil is performing and make adjustments. When using a regulated mod, it will either stop working or display an error message. The mechanical mod will still fire, allowing the user to make adjustments without waiting for the mod to reset or clear error codes. So while it's not a requirement to use mech mods when rebuilding atomizers, most rebuilders tend to prefer them. Sub-Ohm Vaping (Extremely low resistance vaping) First of all, if you are a novice vaper DO NOT ATTEMPT SUB-OHM VAPING. If you don't thoroughly understand Ohm's Law, amperage calculations, and battery c-ratings, then do not under any circumstances attempt sub-ohm vaping. It can cause serious injury and property damage if not done properly. Now that the obligatory safety warnings are out of the way, sub-ohm vapers tend to prefer mech mods because the lack of circuity ensures that there are no electronic protections. A mechanical mod will fire anything that you put on it, including extremely low resistance items. Regulated devices will display an error message or completely shut off if the resistance is too low. By definition, mechanical mods will not do this and will fire regardless of the resistance level. Other reasons While sub-ohm vaping and rebuildable atomizers are two of the most common practical reasons to use a mechanical mod, there are other reasons why people choose to use mechanicals: Simplicity of design - Mechanical mods tend to have an extremely clean and simple, sleek look to them that appeals to lots of vapers. Durability - As mentioned before, the lack of electronic circuitry ensures that most mechanical mods will last a long time. There are no electronics that can malfunction. Bottom firing buttons - Since the button has to be in contact with the battery, most mechanical mods will have a bottom firing button. They are currently popular - Honestly, this is probably the most common reason amongst those who aren't total vaping nerds. Mechanicals have exploded in popularity lately are the coolest thing in vaping at the moment. When it comes down to it, deciding whether to use a mechanical mod or a regulated variable voltage mod is a matter of personal preference. So which type of mod do you vape with?