These genuine, 10-rib, Rotrex supercharger pulley rings have been designed for the C15, C30 & C38 supercharger range (not including the C38-R). Available in 9 different sizes, they allow you to get the exact speed required for your particular application. 
 
Made from lightweight billet aluminium
10-rib pulley design
Hardwearing, black anodised finish
Simple to install 
Can be retrofitted to older Rotrex superchargers with steel pulley rings