Sudio B1 is a device with a level 4 water protection rating, which means that the headset is water-resistant. At this level, the headset can handle heavy rain, sweat, and the occasional accidental splash.
IPX is an official third-party rating that is awarded through a series of tests. Sudio B1 is also completely sweat-proof and can be used during exercise.
However, for an IPX 4 rating, we would like to communicate that there is no guarantee that the headset will remain fully operational after activities like swimming or showering with them.