FYI, the Sea to Summit Big River dry bags have loops welded on to the sides, so you have better options for lashing the thing down. I've got a 35L one that works well.
Big River Dry Bag with Sling Strap
Lash to kayaks, bikes and 4WDs with confidence, or add a Dry Bag Sling for comfortable hands-free carrying. Big River Dry Bags are a durable and abrasion resistant storage option that uses a strong 420D nylon fabric. If your idea of outdoor recreation involves challenging water sports like...
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