Coupling components to an underlying substrate using a composition of a polymer and magnetic material particles. The underside of the flex arm rests on a thin bar formed in a lower spacer layer beneath which lies a base layer including an electromagnet. Each insert exhibits electrical connecting devices which cannot be rotated relative to it. Tension in the balloon bodies gives rise to internal pressures when the balloons are filled. s, avermectins, ivermectin, and milbemycin.