The IPX3 rating indicates the level of water resistance of electronic devices. The abbreviation IP stands for Ingress Protection, which is an internationally recognized standard for evaluating device protection. The letter X in the first position indicates that the product has not been tested for resistance against the ingress of solid particles, such as dust. The digit 3 in the second position specifies that headphones, a speaker, or an MP3 player are protected against spraying water. In practice, this means the device can withstand rain or heavy perspiration during sports, provided water hits it at an angle of up to 60° from the vertical. However, such a device is not waterproof and is therefore not suitable for submersion in water or for use in a shower, for instance.