The invention is directed to a novel class of steroids which exhibit potent antiprogestational activity. The fan is generally parallelepiped, and defines four mounting holes in corners thereof. In a specific and non-limiting example of implementation the phase relationship is 90 degrees. The first connection portion is formed from bending the substrate. The sleeve thickness near the chamber can be made relatively thick to avoid flexing or bending under differential pressure because the net force to shift the sleeve is from differential pressure on the piston rather than the piston areas created by the upper and lower seals. Each memory element accepts a common clock.