An external lightweight breast prosthesis comprising an elastomeric polyurethane skin filled with copolymer gel filler comprising a mixture of mineral oil, thermoplastic copolymer and glass microspheres and initially configured to approximate the shape of a natural breast wherein the breast prosthesis can be reconfigured to be customized to the individual wearer by subjecting the prosthesis to heating, reshaping, and followed by cooling until the prosthesis retains its new shape.
