Most Basic of all Spot trackers has Functions runs on 3x AAA Batteries run time 3 days. This unit is good for a hike if you do not require tracking

Pros	Cons
Gives Emergency GPS location and calls for help	Only reports is location when a button is pushed
Can call for non emergency help	High Equipment Cost
Can send ok message	Requires yearly registration
Work every were you can see a good amount of open sky
Easy to use

See Spot page for more about Spots

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