Garmin GPSMAP 66i Manual
https://www8.garmin.com/manuals/webhelp/gpsmap66i/EN-US/GPSMAP_66i_OM_EN-US.pdf
InReach Messenger User Manual
InReach Explorer+ User Manual
InReach Mini User Manual
Inreach Mini2 User Manual
How to Send a Message to an InReach Device:
https://support.garmin.com/en-US/?faq=o4sYSXP4LC8KhFNWJEVPI7
ACR Resqlink PLB400 User Manual
https://www.acrartex.com/wp-content/uploads/downloads/1591/Product_Manual_Y1-03-0343B.pdf
ACR Resqlink PLB375 User Manual
https://www.acrartex.com/wp-content/uploads/downloads/935/USA_Product_Manual_ResQLink__ACR.pdf