IP and IK are international industrial standards referring to degrees of ‘ingress protection’ for electrical devices.

IP67 standard: First digit 6x. Dust-tight. Full protection against interior injurious dust. That means dust cannot harm the operation of the phone. Second digit x7. Water-proof. Submersible under water up to 1m depth. Please note that the IP rating of the device does not make it resistant to all kinds of liquid, pressurized water and salt/sea water can harm the phone even with a high IP rating.