Have a look at this review by Charis of Global Darts:
Performance Darts were created by the young English dart player Anthony Urmston-Toft who played for some time on the PDC circuit but then joined the BDO. Urmston-Toft for a long time already gets his teeth in all the different darts on the market, has tried more or less everything and thought about how a "perfect" Dart could look. The Perfomance Darts are the result of his thoughts and he thinks he now put darts on the market which might really be suitable for every dart player - darts from a dart player for dart players.
The Performance Darts are from 90 percent tungsten and they are produced in England. You can buy them in 19, 21 and 23 g and at the moment only in the Darts Performance Centre Shop on