An individual identification device and a method for extracting an iris region which can extract the iris region with high accuracy even if the shape of a pupil is not circular as in the case of a horse, cattle or the like. Implicit profiles are derived from the selections of resources by a user without requiring the user to specify any rules by which selections are made. The shell defines an interior void and is formed from a polymer material that extends around substantially all of the void. In one embodiment this is achieved by applying one of the elements to the surface of a solid rod of glass or ceramic and the other element to a portion which has been machined to leave an air pocket under a thin cylindrical wall of the rod material. The conductive plate may be electrically connected to the thermal safety device and mounted in the insulating holder around the thermal safety device.