The Samsung 30Q is a stalwart for those looking for the most capacity you can squeeze out of an 18650, without too large of a compromise in output. These cells are rated for 20A continuous discharge at around 3.7V, but above that you shouldn't push these any further as they're only technically a 15A battery. So, basically, don't use these for mech mods, unless you'd like a wispy cloud that lasts all day.
What's in the box:
Your choice of: