LifeProof NeXT for Galaxy Note 9
If you're coming from an iPhone you've probably owned or seen a LifeProof case. They're one of the first brands to offer an extremely tough and rugged case that was waterproof for the iPhone.
Now, they've created the first-ever Lifeproof Galaxy case. This 2-piece case has six layers of protection that snap together to form a super-strong case that's slim and pocket-friendly. The inner lining seals everything off from dust, dirt, and to a degree even water, even though the Note 9 is IP68 dust and water-resistant already. Basically, you're getting a second layer of protection from the elements, not to mention water CAN still damage your phone, it just "shouldn't".
With this case, you can truly rest easy knowing the Note 9 is safe from almost any situation. They even have a transparent mesh that protects the speaker grill from debris. They thought of everything.