Overview
Garmin is a world leader in GPS products and technology. In 2016 they acquired DeLorme, and added the popular inReach Satellite Communication and Navigation products to the Garmin family. 

Garmin satellite communicators are extremely popular for use in sailplanes.  They communicate through the IRIDIUM satellite network - so you are never out of reach. 
They are used to send GPS position and altitude tracking updates at  regular intervals and display your position and altitude on tracking web sites - so your friends can follow your flight. 
Of course, the tracking could come in very handy in an emergency.  Likewise the ability to send and receive emails and text messages could be very important in an emergency. 
Several preset messages can be sent with a few button presses to send messages such as, "Still Flying", "Landed-out - Fine, but need a retrieve", "Done Flying - Home Safe". 
Emergency rescue services can also be called - if necessary.

here

Feature
	inReach Mini 2	inReach Messenger	GPSMAP 67i
Price	$399.99	$299	$599
Two-way messaging
Global satellite service with Iridium
Two-way global interactive SOS
Tracking location sharing
Cloud storage and trip planning
Pair with mobile devices
Weather
Routes, waypoints and tracks
QWERTY keyboard (on-screen) for custom text entry
Breadcrumb trail
Built-in navigation sensors (Digital compass, barometric altimeter, and accelerometer)
Preloaded DeLorme TopoActive maps
Downloadable BlueChart Marine Maps
Downloadable BirdsEye Satellite Image Maps
Battery Life with 10 minute tracking	- Up to 14 days at 10-minute tracking send interval with standard activity recording with full sky view  - Up to 4 days with moderate tree cover (default)  - Up to 5 days at 10-minute tracking send interval with high detail activity recording with full sky view  - Up to 2 days with moderate tree cover  - Up to 30 days at 30-minute tracking send interval with standard activity recording with full sky view  - Up to 10 days with moderate tree cover  - Up to 1 year when powered off	- Up to 28 days with a message or location sent every 10 minutes with full sky view; up to 14 days with moderate tree cover - Up to 6 days with a message or location sent every 2 minutes with full sky view; up to 3 days with moderate tree cover - Up to 46 days with a message or location sent every 30 minutes with full sky view; up to 23 days with moderate tree cover - Up to 1 year when powered off	- Up to 165 hours with inReach® enabled with 10 minute tracking - Up to 180 hours in GPS Mode - Up to 425 hours in Expedition mode with inReach enabled - Up to 840 hours in Expedition mode
Display Size and Type	Monochrome 0.9"W x 0.9"H 1.27" diag. (23 x 23 mm) 176 x 176 pixels	Monochrome 1" x 0.43", 1.08" diag.  (2.53 x 1.1 cm 2.74 cm diag.) 160 x 68 pixels	Transflective color TFT Display size: 1.5"W x 2.5"H x 3" diag (3.8 x 6.3 cm x 7.6 cm) 240 x 400 pixels
Size of Unit Weight	2.04” x 3.90” x 1.03” (5.17 x 9.90 x 2.61 cm) 3.5 oz (100 g)	3.1" x 2.5" x 0.9" ( 7.8 x 6.4 x 2.3 cm) 4oz (113.9 g)	2.5” x 6.4” x 1.4” (6.2 x 16.3 x 3.5 cm) 8.1 oz (230 g) with batteries