* adb shell getprop
** will get you the properties of the phone
* If you only flash gecko/gaia and looking to figure out which base build you have you can use : https://github.com/Mozilla-TWQA/B2G-flash-tool/blob/master/check_versions.sh#L89
adb shell cat /system/build.prop | grep 'ro.build.version.incremental'
adb shell cat /system/build.prop | grep 'ro.build.date='
or
adb shell getprop ro.build.version.incremental
adb shell getprop ro.build.date
== Internal Storage ==