Containment systems for use with portable power modules trailerable over public roads and capable of providing at least approximately one megawatt of electrical power. The interface includes a memory and a directors interconnected through an interface state data bus and end-user data busses. The assemblies are useful for insertion into bone and connecting a foreign object to bone via a polyaxial coupling mechanism. The audio transducer can pivot on a pivot tube 142 comprising a pivotable stem to accommodate the left ear or right ear of the user.