I just downloaded the photo and there is something weird about the left slider, as if it was outside the slider area and added to the photo. A few other abnormalities, too. The color appears as if it's a metallic purple - not silver.
Cheers,
Gary
But the Tyros 4 also has such a slider on the left of the other 8 sliders with a shorter sliding scope. Look at this link and enlarge the picture: