RE: Some more tank question,Upgrades,kits,clubs etc.
By tuning it, I mean you can adjust the distance of it from the end of the barrel, essentially narrowing the beam. Clubs have rules for both tube diameter and distance to keep it fair, but I find it more fun pulling it back further, making it harder to hit an opponent. You can also change the emitter itself for differnt range and patterns as well as lighten the resistance for more range.
The flash and IR emitters are two different units. They can both be put in the barrel (IR should be the outermost) but again, different clubs have different rules of this, so you need to check.