An external-magnet-type magnetic circuit includes an iron core and at least one composite magnet coaxially mounted around the iron core. The connections are attached to the cylinder barrel by means of soldered joints to achieve a good surface finish and thereby also an optically appealing appearance together with a reliable mounting of the pressure connections. On the outer side of the inner side-walls, an antifreeze zone is defined. After this data set has been established, the test golfer takes a golf swing with a golf club, while performance parameters for the swing are measured. The composition being a mixture of at least two polyolefin-based polymer resins, which are a first soft and flexible resin and a second and heat-resistance provider resin; at least one compatibilizing and coupling agent; at least one flame retardant; at least one antioxidant; at least one lubricant and optionally at least one nanometric clay. An opposite voltage polarity is caused on the bitlines due to the logic 1 in the memory cells.