Read carefully: this is not the new model. It does not work with newer bike trailers. The listing is up for the third time because buyers misunderstood this.

This is model 20101000.
I used it on a Thule Chariot Cougar and it works on that and some older model. The bar is extensible and works with single and double bike trailers.
See in the pictures to check what it comes with.

It is in really good conditions, used with one child only.

https://www.thule.com/sv-se/bike-trailers/bike-trailer-accessories/thule-infant-sling-_-20101000