Unknown. Help us by suggesting a value. (Sennheiser HD 450BT)
Unknown. Help us by suggesting a value. (Sony WH-CH700N)
The first number of the IP rating refers to protection against dust, while the second number refers to protection against liquid. E.g. a first number of 6 denotes that it is completely dustproof, and a second number of 7 denotes that the device can withstand full immersion in water.
Ingress Protection (IP) rating: is this important to you?