The Individual First Aid Kit (IFAK) is one of the key parts of your kit. Whether you’re an assaulter, sniper, medic or a prepared citizen, when carrying a firearm or if wearing body armor, you should have an IFAK and tourniquet present. The very minimum is a tourniquet readily accessible and deployable for self-aid.
Equipment is one of the biggest issues I see while training people and seeing setups over the internet. Contrary to popular belief, you should only be stocking your IFAK with equipment that you know how to use, as well as what your fellow team members. You don’t want to have a dude walk up to you, uncap an ARS needle, and say “this looks a little long for an IV.” This is why all the IFAK’s the Marines carry don’t have ARS needles and scalpels (love you guys). There’s a reason medical personnel carry more bags around with more advanced equipment.
The minimum equipment that should be carried in an IFAK includes a tourniquet, two chest seals, and a pressure dressing. Additional equipment that is strongly encouraged is an individually sized NPA, Combat Wound Medication Pack, combat gauze (or similar hemostatic dressing), ARS needle (based on training), water purification tablets (depending on mission set), eye shield, and MARK1 kit (depending on mission set).