Abstract: A packaging product and a method of closing a packaging product are provided. Closing a packaging product may include providing a first member of the packaging product having an aperture therein and providing a bubble rivet extending through the aperture and having an expanded hollow head portion on one side of the aperture with a neck portion of the bubble rivet being provided in the aperture. The hollow head portion of the bubble rivet is breakable to enable withdrawal of the head portion through the aperture thereby non-reversibly opening the packaging product.

Abstract: A packaging product and a method of closing a packaging product are provided. Closing a packaging product may include providing a first member of the packaging product having an aperture therein and providing a bubble rivet extending through the aperture and having an expanded hollow head portion on one side of the aperture with a neck portion of the bubble rivet being provided in the aperture. The hollow head portion of the bubble rivet is breakable to enable withdrawal of the head portion through the aperture thereby non-reversibly opening the packaging product.

Abstract: A suspension system suitable for a flux gate compass having compass windings (14) includes a ball joint (4,5,6) which permits both tilt and twist about a vertical axis, and a separate alignment element (16) for causing the windings to follow twisting motion of the fixed structure. The alignment element takes the form of a flexible printed circuit made into a double spiral form and carrying electrical conductors to provide the electrical connections to the windings. A zig-zag shape may be used instead of a spiral. The suspension does not suffer from the geometric imperfections of a Hooke's joint and avoids the need for separate flexible conductors which can interfere with the suspension operation and can break.