How can Maytech Ensure Their Inrunner Motor Waterproof ?

Maytech Inrunner fully waterproof motor upgraded to Water-sealed from Oil-sealed, Better technology to prevent water-in and extend motor lifespan.

Water-seal has 2 parts as the following pictures:

2pcs strong hardness ceramic rub with each other, metal ring part spins together with shaft and ball bearing, in this way can prevent abrasion between shaft and water-seal part, and extend motor lifespan.

Which of Maytech motors are Fully Waterproof with water-sealed craft?

Maytech MTI65162 Brushless Inrunner Motor for Efoil/Hydrofoil:

Maytech MTI85165 Brushless Inrunner Motor for Efoil/Esurf

Maytech MTI120116 Brushless Inrunner Motor for Esurf/RC Boat, Jetski, Jetboard, etc.,