Those are nice but they get left behind by EMS. I'm guilty of it too and I know to look for them. When we get called out on a crash or other trauma we try to asses, package and roll as fast as possible and just never spend time looking for those on keys and such. Keep them in a pocket of your clothes, not jacket. Your clothes will always make it to the ER with you. Your leathers may get cut off and left at the scene but we cut the clothes of in the squad. Trauma centers protocol is to have you naked on arrival so clothes are cut off in route but left on the cot so keep it in your pockets or I have seen a few times, sharpied on your chest. Can also be in or on your helmet too as we will most always take the helmet with us to the ER for the doc to see point of impact. On your keys or under your seat will 99.9% of the time be left behind. If you have an alergy to a drug, rare blood type, religious believe against treatment ect the absolute best is written on your chest with a sharpie.