https://en.wikipedia.org/wiki/Emergency_position-indicating_...
https://oceansignal.com/products/plb1/
You buy it, you never pay anything else, it works all over the planet, in extreme conditions, you never need to charge its battery (good for 7+ years), and most importantly, it communicates with an exclusive satellite constellation dedicated to search and rescue, operated by national governments. Your emergency call is handled directly by local government agencies, the military in many parts of the world, who have a duty to respond to the emergency - in accordance with international treaties.
https://en.wikipedia.org/wiki/International_Cospas-Sarsat_Pr...