IP and IK are international industrial standards referring to degrees of ‘ingress protection’ for electrical devices. The IP standard is defined in the international standard IEC 60529 (equivalent of the European standard EN 60529). The IK standard is defined in the international standard IEC 62262:2002 (equivalent of the European standard EN 62262):
First digit: 64
Dust tight. No ingress of dust.
Second digit: 64
Splash resistant. Protected against splashed water from all directions. Splashed water cannot harm the operation of the phone.
Shock proof. Phone can withstand impacts of up to 0.35 joule.