Say no to temporary plastic bags with Sea to Summit nano packs.
Got this recently and highly impressed by the quality. They are almost size of a chicken egg.
Other stores are selling one pack for $29 or more so getting 4 packs is pretty good deal.
Also available in their ebay store if anyone want to use gift card or Cashback.
https://www.ebay.com.au/itm/373775991400
$12.90 delivery, except $15 to TAS, NT, WA.
I just get by with the little ones from Woolies..or the bunnings ones for heavy duty not much bigger. I clip it to my normal 30l pack (stays in side) with a little carabiner when out riding and I drop in for groceries etc that wont fit in the back pack. this would be worse I guess, Dat price !!!