Mountain Bike chain tensioner

This project is meant to solve bike chain lashing when riding offroad.
Generally, in such situations, chain jumps out and you will know it just when you will push on pedals again in the need of traction :(

I designed this item passing through several improvements, releases and tests on the field. This is the last release; the one I considered fully working.

I have been using it on a Cannondale Rize 120, but I guess it will fit many other different bikes.
Now my new bike has chai