“Some internal parts are steel and will quickly rust.” LOL

Pretty weak for Arca Swiss Monoball – a top class tripod head:

Cleaning and Servicing Your Monoball

Water Damage: If your Monoball is accidentally immersed in water it will need to come in for repair. Some internal parts are steel and will quickly rust. After it has dried, it may seem to function, but if it is left in a rusting condition, eventually fragments of rust will work themselves into the clamping mechanism and start scratching the ball itself. The sooner you send it to us for repair, the less expensive the repair will be…

Source: Precision Camera Works – official dealer and service partner of Arca Swiss in the US