Duster question

[jerboa]

Hi, Newbie here.  Sorry if this is in the wrong place.

Just had someone give me an Australian Outback Outfitters Denim full length duster.  It's beautiful though not fully period accurate.

My question is this.  It has a full detachable cape and there are two foot long straps dangling from the bottom hem of the cape.
What are the straps for?

Thanks

[Major 2]

In my case, they are to hang up on just about everything when mounting or a tree branch when riding ...

They are designed to keep the cap from flapping in wind by going under the arms they do that reasonably well and when you roll the coat up they are used to wrap and lash it to the saddle.