The redundant domain of the 2f interpenetrating couplers is a 2f RITE and includes one whole COUPLER and 4 1f RITES. RITE and COUPLER are not only selfpacking allspace fillers but they also fill space in complementarity with each other in the same way that tetra and octa fill allspace in the IVM. This redundancy domain of interpenetrating couplers expands with frequency. Notice that the 1f coupler constitutes a domain of redundancy between the interpenetrating rhombic dodecahedra in the 2f couplers. These are Cubocta D and Octa C RD (see COUPLER LATTICE).