This is the shoulder strap only!
It fits all models.

Hello! Just to clear up any confusion (a mistake I made), this product is just the sling (the shoulder strap), and does not include the dry bag. The first image is misleading. The strap should fit all models. I have the 13L and the 20L dry bags and the strap fits them well. I cannot say whether they are comfortable to use with dry bags larger than 20L since the strap may become too short.

It's only the sling for the bag without bag!!