Is this grey piece a LEGO part? I have this piece in our box of random LEGO. It doesn’t have any studs to connect to so wonder if it’s even a LEGO piece. 

Added a picture with other pieces for size perspective.
It is not LEGO but a clip for a Playmobil cannon.

https://www.libble.de/playmobil-7683/p/561335/