About IP 68, it is a protection classification offered by an enclosure is shown by the letter IP (Ingress Protection) and two digits. This can be considered a standard to know if the product is qualified what you need. The first digit indicates the level of protection against the dust; the second number indicates the protection against the water.
For the first digit, from 0 to 6, 6 is the highest level, which means that it can totally stop the dust to ingress the product. They put the device in a dust chamber in which talcum powder is in the air to test the device and check if the dust ingress into the body. If the product passes this test, it can get the number 6.
For the second number, 8 is the highest level, from 0 to 8, which means that it is protected against water submersion. In order to test the device, it should be completely immersed in the water and in the certain pressure to make sure that water can not penetrate into the device.
The IP 68 can be considered as a key point while people select the products. Without it, it is very hard to know the level of the protection of the product. In fact, you might buy a so called waterproof product, which could not tell you, how deep or how long the product can be used in the water. That is why we need the IP rating, which can let the consumer know the condition of the product.
While you look for a real waterproof product, the first thing you need to check is the IP rating. If you see the IP68, congratulation, you find a qualified one! However, if the IP rating is lower than that, it is definitely not the waterproof product that you are looking for.