Windit is designed to be universal to all backpacks up to 40cm of length. Typically, that translates to 26L backpacks.
The lenght/volume-ratio depends on the design of your backpack.
To make sure Windit is applicable to your backpack, you should always measure the lenght of you backpack.
If your backpack is longer than 40 cm, Windit can still be attached and used. The functionality will maintain but it can look and feel a bit strange.
If you are interested in a larger version of Windit, sign up to our email and we will let you know when we release it.