I bought a second. These are so useful allowing you to charge up your batteries while on the run and get more flight time from your spark, great design and product add little to the size of my travel kit. It secures and protects the drone and will charge the drone and two additional batteries at the same charging session, while traveling the batteries will charge when electricity isnt nearby.

https://www.youtube.com/watch?v=euxhBR8NjoU