Pheumatic Connector Gap Holder

I don't know what this little thing called, so I'll just name it as Pheumatic connector gap holder.
As I search over the net I do not find any stl for this little guy. Unfortunately, My printer didn't have this little thing in box, the my pheumatic connector's teeth keep scratching the tube and making it easily bite off the wall of the tube and for few times it got jammed.
Thus I have to design this little thing and I think it would come in handy for others who may in need of this.

the thickness is about 1.5mm to 2mm, but you can scale on z direction to make it a custom thickness that suit your connector gap.