i don't understand what it use for ? and class engineer utility slot - utility pouch it mean i can carry max 4 c4, mine right ?
Well, simple. HA has anti-vehicle missiles. Engineers have repair ability, similar to medic who can heal players. Sniper has a warning system (meant to find cloaked players). Only one that doesnt have a 3rd slot is LA, which technically their rocket packs count. Dont really know how else to lay it out.
Then ya apparently I dont understand at all, because everything i listed IS each classes ability slot #3.... Instead of being an *** about someone trying to help you, how about you use a more elaborate explanation and maybe even an example or two of what it actually is you want to know, or can I just chalk you up to a troll?