C.A.T CAT Genuine Official Military Grade Combat Trauma Bleed Control Tourniquet Kit, Black

This is an essential addition to any serious medkit, especially if you're going to have to deal with blunt trauma injuries. The item is sturdy (essential) and one-handed operation is an absolute must not only for self-administration but also because a medic can apply it while retaining one hand free for other purposes. Not only do I have one in my medkit in my bergen but I have two on my plate carrier so that if needed I can pull & apply with either hand should the other be incapacitated. Of course, if you're going to buy a tourniquet you need to learn how to use it, ideally by undertaking a course of instruction from a qualified medic/paramedic. And then you should practice regularly to maintain muscle-memory to make it automatic because if you need to use it, you'll be amped up on adrenalin and it won't be so easy to focus - and it will be impossible to remember that 5-minute YouTube video you watched all those months ago, thinking that's all you'd need in terms of learning how to use it.