It’s just a very small remote controlled switch for the Lego Technic Pneumatic system. As far as I know it’s the smallest RC switch to use. Maybe it is useful for you.

Edit: I use it in my “Mercedes Zetros 2733 Full RC LEGO® Technic Truck“.

Used music:
bwatts “Seven (New Music Remix)”, 2012, CC-BY
http://ccmixter.org/files/bwatts/39793

Referenced video:
Lego The room creations “Lego Pneumatic servo (RC)”
https://www.youtube.com/watch?v=iqpKgrZTxEg