When you buy the waterproof bag, maybe you will consider its waterproof rating due to some outdoor activities such as go hiking, climbing, surfing, fishing, cycling ect. Have high request waterproof rating for waterproof bags.
Compared with vague marketing terms such as waterproof or water resistant, the IPX standard show you a clearer picture of how water resistant the item is.
The digits indicate different meanings. IPX6 indicates protected against high pressure water from everywhere. IPX7 indicates protected against water immersion, can be submerged for 30 minutes in 1-meter deep water. The larger value of each digit, the greater of water resistant. For example, a product rated IPX7 would be better protected against environmental factors than another similar product rated as IPX6.
In general, IPX6 and IPX7 waterproof rating are more than enough for outdoor sports requirement.