IP specifies the protection against solid and/or liquid of an electrical system.
IP rating = Ingress Protection rating.
The IP rating normally has 2 (or 3) numbers.
The first number is in regards to protection against solid objects or materials. The second number is how well it is protected against liquids. The third number (typically omitted) is protection against mechanical impacts.
In most of our products, we will see a rating of IP65 or higher. The “6″ means that it is fully protected from dust. This is the highest rating on the first number. The second number “5″ means that is protected against low pressure jets of water from all directions . This is the lowest you will normally find in any of our lighting products and components (LED’s etc.). The highest rating available is ”9k” which means that it is protected agianst high pressure hosing up to 100 bars. For our products, the highest rating you will typically see is “8″ which means it is protected for long periods of immersion under pressure.
Short and Sweet of it is that when it comes to being weather resistant and durable: a rating of IP 69 is the best but the highest we see is normally IP68, like the SloanLED V-180 or the Apollo.