Actually, according to another thread elsewhere, the PSS10 is not even the designation for these Damptronics. They're known as simply the Bilstein Damptronics, not PSS9 nor PSS10. Adds to the confusion further doesn't it? FYI, PSS9 represents the number of settings each system has, for example, the PSS9 has 9 settings whereas PSS10 has 10.