Mec's can be changed over from any ga .410 through 12 ga (i think 10 ga as well) with conversion kits. I usually focus on the wad guide if i am looking at pictures without the gauge in the description, but it's difficult to tell between a 16 or 12 ga even with clear photo's. You can always take a 12 ga wad with you and see if it fits through the wad guide, but will still have to make the hour drive. I would buy it for that price regardless of gauge. If it is an older press with the steel dies it will have 12 stamped on the crimp starter die and the crimping die. At least my old sizemaster is, but i don't know about the newer presses with plastic dies.
