Definitely try and stick to the Arlo made ones. There have been reports about third party ones allowing water ingress at the connector, which is obviously terrible. Some have said they've ended up putting silicon sealant around the connector. Also you may find your warranty is voided if you use a third party item and damage occurs because of it. Regardless of waterproofness, I'd always recommend trying to keep the camera under an eave or some shelter if possible. Obviously, this is dependent on the item. I use third party silicon skins because they're cheaper and should have no risks