Thank you for your replies.

I had a look at condoroutdoor.com but I can't find the price or the buy button. After googling I found something similar, what do you thing @Jeanette_Isabelle?

https://militarytrained.com/product/military-multifunction-water-resistant-outdoor-bag/

@Montanero do you know if the bag made of nylon is light enough? is there a better material that is sturdy buy light? But I think @hikermor answered this one.

Thanks, @hikermor I agree a well-fitted bag is important, I might just do that. But come back online to make a final purchase

@Pete north face must be expensive, how much did you pay for yours?

@AKSAR thank you for your advice. The terrain is a typical Australian bushland with about 16-22 degrees temperature.