The aluminium diaphragm coupling consists of at least a set of metal laminations (metal or synthetic resin) and two hubs ((single diaphragm coupling). The metal laminations are fastened to the hub by pins, and generally will not loosen or cause The recoil between the disc and the hub.
Some manufacturers can provide two sets of metal laminated couplings, with a rigid part in the middle, and two sides connected to the hub (double diaphragm coupling).