Our kit is exactly waterproof as the others motors on the market, like to Bafang , Bosch or Yamaha.
Like to all others brands we preconize to exposed less as possible the system to the water.
But all is designed for classic mountain bike using, so we sealed the controller with a special resin and the motor and the connections are also waterproof.
We therefore guarantee the system against occasional splashes or small rain (ip4) but the system is not sealed against full water immersion.
The better for wash the motor, use a damp cloth, if you need to clean the the bike with a water jet, don't insist to much on the motor, you can cover the motor and system parts with a plastic bag if it's neccesary...
Then allow the system to dry before using it again.
The batteries are absolutely not water proof, but you will have on the pack a protection bag, if you planning to ride with rain use plastic bag for protect it.