For decades, higher end cameras have included WDR, but they normally tell you what WDR quality level you're buying.
The dB unit is the ratio of the brightest and the dimmest object that can be captured by the camera. This tells you the range where the WDR works. The higher the ratio, the greater the difference between the low light and high light spectrum that the camera can capture and the better your picture will be. This is why high dB ratios are better - they can capture a larger spectrum of lighting conditions.
What is Spectrum Vision WDR?
They don't list the dB ratings, so no one can know. Do different models that claim to have Spectrum Vision all have the same results? Is one model better than another? How do they compare to other WDR products?
You can't know what Spectrum Vision WDR even is, since they aren't telling you anything about the actual specs.