Xtreme Rotaries 13B (2 rotor) Centre Bearing Crank Kit.
 
(NO LONGER AVAILABLE) 
 
Billet EN39 2 rotor Eccentric shaft
Billet 20B style front nut
Billet centre bearing widget kit 
 
Note: These shaft are only avalible at certin times. So best pre ordering if you want to get your hands on one of thse units as they offen sell months or years in advance