These seals are distinct as you can see a "D" in the seal, often called "centre bead seal"
They are interchangeable with the normal o'ring heater seals but they can be used for a multitude of different applications - available in 1.5" (711-4050) & 2" (711-4030) varaints.
Dimensions
1.5"
2"
Approx thickness:
5mm
5mm
Diameter (external):
59mm
75mm
Ideal For
Most often found Balboa, Brett Aqualine, Gecko, Hydroquip, RMF & Thermcore heater manifolds
