I checked the site again and found this:

Life Alert Emergency Response, Inc.
Life Alert provides medical emergency response when seniors experience life threatening events. Life Alert is the only company endorsed by C. Everett Koop, MD, former US Surgeon General. Life Alert appears on TV and in AARP magazine.

Since 1987, Life Alert ® has been in the business of providing emergency response services to the elderly and handicapped on a 24-hour, 7 day a week basis. Life Alert strives to provide the highest quality of services to its consumers.
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Interesting how seniors are mentioned first and handicapped people are
sort of added as an afterthought.

As for how much the service costs, I don't know because the links don't
work. Maybe someone who uses the service in those states will see this
and post some information.