On NSD's site it says the PB 188 unit is capable of 13000 rpm. Here on this site the 250hz is rated at 15000 (even though 16218 has been achieved by superman). Just curious, isn't the PB 188 the same unit as a 250hz model? Does Powerball modify a PB 188 in anyway to enhance its performance?
Not trying to be difficult I just wanted to know if there's a difference between the models.