The external form of the black male develops the retentive element in the acrylic resin that allows the operator to easily change the male attachments. Most problems in usingthe ERA Attachment system stem from the failure to start off with the Black processing male and establish the proper retentive element in the Acrylic resin. It is the use of the black processing male that forms the 0.4mm of resilience in the operation of this attachment system. Process directly to any other male attachment and you loose all the resilience of the attachment and increase the wear factor dramatically. By the same token, leaving in the black male during function of the prosthesis will also damage the attachment and eliminate the resilience. the following page will examine the ERA implant Abutment