Every home and business needs a first aid kit. The problem is that most first aid kits come in an over-stuffed plastic box whose hinges break off, and the minute you open it you can't seem to ever reclose it again.
We carry the 'First Aid Only' brand of first aid kits because they use a metal box and don't over-stuff them. This means you buy the kit once and the thing will last a lifetime. You simply go to the local drug store every few years and replenish it. The box is tough metal with strong hinges, uses two laspes to keep it closed, and holds up to bouncing around in a truck or clumsy office-worker abuse. You'll get your best bang-for-the-buck from the 'First Aid Only' product.
Now, the lower priced first aid kits below carry the basics (various band aids, anitseptic, some gauze, some have tweasers, etc.). And the 'xx Person' sizing is OSHA's suggested quantity for a first aid kit based on likely usage. The bigger units provide a wider range of medical supplies where it's assumed the injury is more severe and/or trained personnel are available.
One way or the other, these first aid kits are the way to go because the rugged over-sized metal box permits you to replenish them, meaning your first aid kit will essentially last forever.