As I have read, not everyone is satisfied with the content. Here is my opinion: A set should be filled in the order of vital necessity and of what is most likely to be needed. Even these two criteria cannot be fulfilled equally by everyone. The best thing to do is to buy a reasonably clever set and customise it. Before buying, it might be a good idea to attend another emergency aid course. If I'm disgusted about giving someone artificial respiration, a respiratory mask is recommended. If I'm at least tough in an emergency, I can keep this space free for something else. If it's a car first-aid kit, then I would definitely want to have a respiratory mask with me because a passer-by who doesn't have anything with them could possibly save me. So you can play around with everything and find the right kit for you.