According to various embodiments, an inflatable penile prosthesis (IPP) includes a rigidly constructed spool valve assembly that is used to direct fluid into and evacuate fluid out of the inflatable penile cylinders. The fluid transfer system transfers fluid from the fluid reservoir to the inflatable penile cylinders and includes the fluid transfer bulb, inlet valve, exhaust valve and spool valve assembly. The cylinder deflate mechanism evacuates fluid from the penile cylinders to the reservoir and includes the deflate actuator, return valve and spool valve assembly.
