We do three types of donkey rugs: Waterproof, Flectalon or Combi.
Flectalon is a thermal rug made with Flectalon and lined with a smart poly/cotton.
It is shower proof but will not be waterproof in rain heavier than a light shower. See what is Flectalon.
Combi is thermal and waterproof. It has a waterproof breathable outer and Flectalon on the inside and lined with a wicking lining.