Clear trends in the newest device are:
- integrated logging
- solar powered ones
- long battery life
- auto on/off (means going into sleep mode and saving power)
The overview is in German only, but I am sure you’ll get the drift!
(akku = battery, wechsel = changeable, anschluss = connection, (spritz)wasserdicht = water-resistant, punkten = points, laudsprecher = loudspeaker)