The Prodigy Umbrella
is your accessory for rainy rounds. Due to the diameter of 135 cm, both you and your bag are very well protected from rain. The square shape prevents the umbrella from rolling away on sloping terrain.
The Prodigy umbrella can of course be inserted in the folded state, but also in the open state, into the umbrella holder of the Prodigy BP-1 V3 backpack.
Here is the link to the manufacturer.