Pentair Kreepy Krauly Legend II Back-Up Valve - Housing O-Ring (E13)
The back-up valve (housing o-ring) is a replacement part that was made by Pentair. The same high-quality materials were used to manufacture the original factory part. Making this a genuine OEM product.
This o-ring was designed specifically for the back-up valve and its purpose is to create a strong tight bond between the outer casing of the valve which acts as a protective cover for the back-up valve's internal gears that could be subject to damage or outside influence which would disrupt the effectiveness of the valve.
The o-ring is black just like most other o-rings you would find for other items but is made from a strong and durable rubber however, it can wear or deteriorate over the length of time and use of the cleaner or depending upon the quality of water in which it resides in so it may need to be replaced to restore the effectiveness back to the valve.