Sidephone does not have an official IP rating, however it was designed to resist minor splashes and exposure to dust.
One of the most common failure points of a device with physical buttons are the physical buttons. Sidephone's swappable keypads remedy this issue, as switching out the keypad takes seconds.
Please do not submerge Sidephone into water. Complete submersion in water will damage the device, affect battery safety, and void warranty. Do what you can to protect the device from water, such as adding approved and official protective cases or covers.